Bicalutamide is available for the treatment of prostate cancer in most developed countries, including over 80 countries worldwide. It is available in 50 mg, 80 mg (in Japan), and 150 mg tablets for oral administration. The drug is registered for use as a 150 mg/day monotherapy for the treatment of LAPC in at least 55 countries, with the U.S. being a notable exception where it is registered only for use at a dosage of 50 mg/day in combination with castration. No other formulations or routes of administration are available or used. All formulations of bicalutamide are specifically indicated for the treatment of prostate cancer alone or in combination with surgical or medication castration. A combined formulation of bicalutamide and the GnRH agonistgoserelin in which goserelin is provided as a subcutaneousimplant for injection and bicalutamide is included as 50 mg tablets for oral ingestion is marketed in Australia and New Zealand under the brand name ZolaCos CP (Zoladex–Cosudex Combination Pack).
Bicalutamide is pregnancy category X, or "contraindicated in pregnancy", in the U.S., and pregnancy category D, the second most restricted rating, in Australia. As such, it is contraindicated in women during pregnancy, and women who are sexually active and who can or may become pregnant are strongly recommended to take bicalutamide only in combination with adequate contraception. It is unknown whether bicalutamide is excreted in breast milk, but many drugs are excreted in breast milk, and for this reason, bicalutamide treatment is similarly not recommended while breastfeeding.
In individuals with severe, though not mild-to-moderate hepatic impairment, there is evidence that the elimination of bicalutamide is slowed, and hence, caution may be warranted in these patients as circulating levels of bicalutamide may be increased. In severe hepatic impairment, the elimination half-life of the active (R)-enantiomer of bicalutamide is increased by about 1.75-fold (76% increase; elimination half-life of 5.9 and 10.4 days for normal and impaired patients, respectively). The elimination half-life of bicalutamide is unchanged in renal impairment.
Bicalutamide monotherapy has been associated with abnormal liver function tests such as elevated liver enzymes in 3.4% of men relative to 1.9% for standard care.Hepatic changes such as marked increases in liver enzymes or hepatitis that necessitated discontinuation of bicalutamide have occurred in approximately 0.3 to 1% of men in clinical trials. Monitoring of liver function during treatment is recommended, particularly in the first few months. In men of advanced age with prostate cancer, bicalutamide monotherapy has been associated with an increase in non-prostate cancer mortality, in part due to an increase in the rate of heart failure. These mortality-related effects are thought to be a consequence of androgen deprivation, rather than a specific drug-related toxicity of bicalutamide.
The side effect profile of bicalutamide in men and women differs from that of other antiandrogens and is considered favorable in comparison. Relative to GnRH analogues and the steroidal antiandrogen (SAA) cyproterone acetate (CPA), bicalutamide monotherapy has a much lower incidence and severity of hot flashes and sexual dysfunction. In addition, unlike GnRH analogues and CPA, bicalutamide monotherapy is not associated with decreased bone mineral density or osteoporosis. Conversely, bicalutamide monotherapy is associated with much higher rates of breast tenderness, gynecomastia, and feminization in men than GnRH analogues and CPA. However, gynecomastia with bicalutamide is rarely severe and discontinuation rates due to this side effect are fairly low. These differences in side effects between bicalutamide monotherapy, GnRH analogues, and CPA are attributed to the fact that whereas GnRH analogues and CPA suppress estrogen production, bicalutamide monotherapy does not lower estrogen levels and in fact actually increases them.
A single oral dose of bicalutamide in humans that results in symptoms of overdose or that is considered to be life-threatening has not been established. Dosages of up to 600 mg/day have been well tolerated in clinical trials, and it is notable that there is a saturation of absorption with bicalutamide such that circulating levels of its active (R)-enantiomer do not further increase above a dosage of 300 mg/day. Overdose is considered unlikely to be life-threatening with bicalutamide or other first-generation NSAAs (i.e., flutamide and nilutamide). A massive overdose of nilutamide (13 grams, or 43 times the normal maximum 300 mg/day clinical dosage) in a 79-year-old man was uneventful, producing no clinical signs, symptoms, or toxicity. There is no specific antidote for bicalutamide or NSAA overdose, and treatment should be based on symptoms, if any are present.
Bicalutamide is almost exclusively metabolized by CYP3A4. As such, its levels in the body may be altered by inhibitors and inducers of CYP3A4. (For a list of CYP3A4 inhibitors and inducers, see here.) However, in spite of the fact bicalutamide is metabolized by CYP3A4, there is no evidence of clinically significant drug interactions when bicalutamide at a dosage of 150 mg/day or less is co-administered with drugs that inhibit or induce cytochrome P450enzyme activity.
Because bicalutamide circulates at relatively high concentrations and is highly protein-bound, it has the potential to displace other highly protein-bound drugs like warfarin, phenytoin, theophylline, and aspirin from plasma binding proteins. This could, in turn, result in increased free concentrations of such drugs and increased effects and/or side effects, potentially necessitating dosage adjustments. Bicalutamide has specifically been found to displace coumarinanticoagulants like warfarin from their plasma binding proteins (namely albumin) in vitro, potentially resulting in an increased anticoagulant effect, and for this reason, close monitoring of prothrombin time and dosage adjustment as necessary is recommended when bicalutamide is used in combination with these drugs. However, in spite of this, no conclusive evidence of an interaction between bicalutamide and other drugs was found in clinical trials of nearly 3,000 patients.
The affinity of bicalutamide for the AR is relatively low as it is approximately 30 to 100 times lower than that of DHT, which is 2.5- to 10-fold as potent as an AR agonist as testosterone in bioassays and is the main endogenousligand of the receptor in the prostate gland. However, typical clinical dosages of bicalutamide result in circulating levels of the drug that are thousands of times higher than those of testosterone and DHT, allowing it to powerfully prevent them from binding to and activating the receptor. This is especially true in the case of surgical or medical castration, in which testosterone levels in the circulation are approximately 95% reduced and DHT levels in the prostate gland are about 50 to 60% reduced. In women, levels of testosterone are substantially lower (20- to 40-fold) than in men, so much smaller doses of bicalutamide (e.g., 25 mg/day in the hirsutism studies) are necessary.
Blockade of the AR by bicalutamide in the pituitary gland and hypothalamus results in prevention of the negative feedback of androgens on the hypothalamic–pituitary–gonadal axis (HPG axis) in males and consequent disinhibition of pituitary luteinizing hormone (LH) secretion. This, in turn, results in an increase in circulating LH levels and activation of the gonadal production of testosterone and by extension production of estradiol. Levels of testosterone have been found to increase 1.5- to 2-fold (59–97% increase) and levels of estradiol about 1.5- to 2.5-fold (65–146% increase) in men treated with 150 mg/day bicalutamide monotherapy. In addition to testosterone and estradiol, there are smaller increases in concentrations of DHT, sex hormone-binding globulin, and prolactin. Estradiol levels with bicalutamide monotherapy are similar to those in the low-normal premenopausal female range while testosterone levels generally remain in the high end of the normal male range. Testosterone concentrations do not typically exceed the normal male range due to negative feedback on the HPG axis by the increased concentrations of estradiol. Bicalutamide influences the HPG axis and increases hormone levels only in men and not also in women. This is due to the much lower levels of androgens in women and their lack of basal suppression of the HPG axis in this sex. As evidenced by its effectiveness in the treatment of prostate cancer and other androgen-dependent conditions, the antiandrogenic actions of bicalutamide considerably exceed any impact of the increased levels of testosterone it results in. However, the elevated levels of estradiol remain unopposed by bicalutamide and are responsible for the gynecomastia and feminizing side effects it causes in men. Although bicalutamide monotherapy increases gonadotropin and sex hormone levels in men, this will not occur if bicalutamide is combined with an antigonadotropin such as a GnRH analogue, estrogen, or progestogen, as these medications maintain negative feedback on the HPG axis.
NSAA monotherapy, including with bicalutamide, shows a number of tolerability differences from methods of androgen deprivation therapy that incorporate surgical or medical castration. For example, the rates of hot flashes, depression, fatigue, and sexual dysfunction are all much higher with GnRH analogues than with NSAA monotherapy. It is thought that this is because GnRH analogues suppress estrogen production in addition to androgen production, resulting in estrogen deficiency. In contrast, NSAA monotherapy does not decrease estrogen levels and in fact increases them, resulting in an excess of estrogens that compensates for androgen deficiency and allows for a preservation of mood, energy, and sexual function.Neurosteroids that are produced from testosterone like 3α-androstanediol and 3β-androstanediol, which are ERβ agonists and the former a potent GABAA receptorpositive allosteric modulator, may also be involved. In the specific case of sexual dysfunction, an additional possibility for the difference is that without concomitant suppression of androgen production, blockade of the AR by the bicalutamide in the brain is incomplete and insufficient to markedly influence sexual function.
Under normal circumstances, bicalutamide has no capacity to activate the AR. However, in prostate cancer, mutations and overexpression of the AR can accumulate in prostate gland cells which can convert bicalutamide from an antagonist of the AR into an agonist. This can result in paradoxical stimulation of prostate cancer growth with bicalutamide and is responsible for the phenomenon of the antiandrogen withdrawal syndrome, where antiandrogen discontinuation paradoxically slows the rate of prostate cancer growth.
In transgender women, breast development is a desired effect of antiandrogen or estrogen treatment. Breast development and gynecomastia induced by bicalutamide is thought to be mediated by increased activation of the ER secondary to blockade of the AR (resulting in disinhibition of the ER in breast tissue) and increased levels of estradiol. In addition to fat deposition, connective tissue growth, and ductal development, bicalutamide has been found to produce moderate lobuloalveolar development of the breasts. However, full lobuloalveolar maturation necessary for lactation and breastfeeding will not occur without progestogen treatment.
Bicalutamide monotherapy seems to have minimal effect on testicularspermatogenesis, testicular ultrastructure, and certain aspects of male fertility. This seems to be because testosterone levels in the testes (where ≈95% of testosterone in males is produced) are extremely high (up to 200-fold higher than circulating levels) and only a small fraction (less than 10%) of the normal levels of testosterone in the testes are actually necessary to maintain spermatogenesis. As a result, bicalutamide appears to not be able to compete with testosterone in this sole part of the body to an extent sufficient to considerably interfere with androgen signaling and function. However, while bicalutamide does not seem to be able to adversely influence testicular spermatogenesis, it may interfere with AR-dependent sperm maturation and transport outside of the testes in the epididymides and vas deferens where androgen levels are far lower, and hence may still be able to impair male fertility. In addition, the combination of bicalutamide with other medications, such as estrogens, progestogens, and GnRH analogues, can compromise spermatogenesis due to their own adverse effects on male fertility. These medications are able to strongly suppress gonadal androgen production, which can severely impair or abolish testicular spermatogenesis, and estrogens also appear to have direct and potentially long-lasting cytotoxic effects in the testes at sufficiently high concentrations.
Though its absolute bioavailability in humans is unknown, bicalutamide is known to be extensively and well-absorbed. Its absorption is not affected by food. The absorption of bicalutamide is linear at doses up to 150 mg/day and is saturable at doses above this, with no further increases in steady-state levels of bicalutamide occurring at doses above 300 mg/day. Whereas absorption of (R)-bicalutamide is slow, with levels peaking at 31 to 39 hours after a dose, (S)-bicalutamide is much more rapidly absorbed. Steady-state concentrations of the drug are reached after 4 to 12 weeks of treatment independently of dosage, with a 10- to 20-fold progressive accumulation in levels of (R)-bicalutamide. The long time to steady-state levels is the result of bicalutamide's very long elimination half-life.
Bicalutamide is metabolized in the liver. (R)-Bicalutamide is metabolized slowly and almost exclusively via hydroxylation by CYP3A4 into (R)-hydroxybicalutamide. This metabolite is then glucuronidated by UGT1A9. In contrast to (R)-bicalutamide, (S)-bicalutamide is metabolized rapidly and mainly by glucuronidation (without hydroxylation). None of the metabolites of bicalutamide are known to be active and levels of the metabolites are low in plasma, where unchanged biclautamide predominates. Due to the stereoselective metabolism of bicalutamide, (R)-bicalutamide has a far longer terminal half-life than (S)-bicalutamide and its levels are about 10- to 20-fold higher in comparison following a single dose and 100-fold higher at steady-state. (R)-Bicalutamide has a relatively long elimination half-life of 5.8 days with a single dose and 7 to 10 days following repeated administration.
Bicalutamide is eliminated in similar proportions in feces (43%) and urine (34%), while its metabolites are eliminated roughly equally in urine and bile. The drug is excreted to a substantial extent in unmetabolized form, and both bicalutamide and its metabolites are eliminated mainly as glucuronideconjugates. The glucuronide conjugates of bicalutamide and its metabolites are eliminated from the circulation rapidly, unlike unconjugated bicalutamide.
First-generation NSAAs including bicalutamide, flutamide, and nilutamide are all synthetic, nonsteroidal anilide derivatives and structural analogues of each other. Bicalutamide is a diarylpropionamide while flutamide is a monoarylpropionamide and nilutamide is a hydantoin. Bicalutamide and flutamide, though not nilutamide, can also be classified as toluidides. All three of the compounds share a common 3-trifluoromethylaniline moiety. Bicalutamide is a modification of flutamide in which a 4-fluorophenylsulfonyl moiety has been added and the nitro group on the original phenyl ring has been replaced with a cyano group.Topilutamide, also known as fluridil, is another NSAA that is closely related structurally to the first-generation NSAAs, but, in contrast to them, is not used in the treatment of prostate cancer and is instead used exclusively as a topical antiandrogen in the treatment of pattern hair loss.
The second-generation NSAAs enzalutamide and apalutamide were derived from and are analogues of the first-generation NSAAs, while another second-generation NSAA, darolutamide, is said to be structurally distinct and chemically unrelated to the other NSAAs. Enzalutamide is a modification of bicalutamide in which the inter-ring linking chain has been altered and cyclized into a 5,5-dimethyl-4-oxo-2-thioxoimidazolidine moiety. In apalutamide, the 5,5-dimethyl groups of the imidazolidine ring of enzalutamide are cyclized to form an accessory cyclobutane ring and one of its phenyl rings is replaced with a pyridine ring.
The first nonsteroidal androgens, the arylpropionamides, were discovered via structural modification of bicalutamide. Unlike bicalutamide (which is purely antiandrogenic), these compounds show tissue-selective androgenic effects and were classified as selective androgen receptor modulators (SARMs). Lead SARMs of this series included acetothiolutamide, enobosarm (ostarine; S-22), and andarine (acetamidoxolutamide or androxolutamide; S-4). They are very close to bicalutamide structurally, with the key differences being that the linker sulfone of bicalutamide has been replaced with an ether or thioether group to confer agonism of the AR and the 4-fluoro atom of the pertinent phenyl ring has been substituted with an acetamido or cyano group to eliminate reactivity at the position.
A few radiolabeled derivatives of bicalutamide have been developed for potential use as radiotracers in medical imaging. They include [18F]bicalutamide, 4-[76Br]bromobicalutamide, and [76Br]bromo-thiobicalutamide. The latter two were found to have substantially increased affinity for the AR relative to that of bicautamide. However, none of these agents have been evaluated in humans.
5N-Bicalutamide, or 5-azabicalutamide, is a minor structural modification of bicalutamide which acts as a reversible covalent antagonist of the AR and has approximately 150-fold higher affinity for the AR and about 20-fold greater functional inhibition of the AR relative to bicalutamide. It is among the most potent AR antagonists to have been developed and is being researched for potential use in the treatment of antiandrogen-resistant prostate cancer.
Bicalutamide was first studied in a phase Iclinical trial in 1987 and the results of the first phase II clinical trial in prostate cancer were published in 1990. The pharmaceutical division of ICI was split out into an independent company called Zeneca in 1993, and in April and May 1995, Zeneca (now AstraZeneca, after merging with Astra AB in 1999) began pre-approval marketing of bicalutamide for the treatment of prostate cancer in the U.S.. It was first launched in the U.K. in May 1995, and was subsequently approved by the U.S. FDA on 4 October 1995, for the treatment of prostate cancer at a dosage of 50 mg/day in combination with a GnRH analogue.
Following its introduction for use in combination with a GnRH analogue, bicalutamide was developed as a monotherapy at a dosage of 150 mg/day for the treatment of prostate cancer, and was approved for this indication in Europe, Canada, and a number of other countries in the late 1990s and early 2000s. This application of bicalutamide was also under review by the FDA in the U.S. in 2002, but ultimately was not approved in this country. In Japan, bicalutamide is licensed at a dosage of 80 mg/day alone or in combination with a GnRH analogue for prostate cancer. The unique 80 mg dosage of bicalutamide used in Japan was selected for development in this country on the basis of observed pharmacokinetic differences with bicalutamide in Japanese men.
Subsequent to negative findings of bicalutamide monotherapy for LPC in the EPC trial, approval of bicalutamide for use specifically in the treatment of LPC was withdrawn in a number of countries including the U.K. (in October or November 2003) and several other European countries and Canada (in August 2003). In addition, the U.S. and Canada explicitly recommended against the use of 150 mg/day bicalutamide for this indication. The drug is effective for, remains approved for, and continues to be used in the treatment of LAPC and mPC, on the other hand.
The patent protection of bicalutamide expired in the U.S. in March 2009 and the drug has subsequently been available as a generic, at greatly reduced cost.
Bicalutamide was the fourth antiandrogen (and the third NSAA) to be introduced for the treatment of prostate cancer, following the SAA CPA in 1973 and the NSAAs flutamide in 1983 (1989 in the U.S.) and nilutamide in 1989 (1996 in the U.S.). It has been followed by abiraterone acetate in 2011, enzalutamide in 2012, apalutamide in 2018, and darolutamide in 2019, and may also be followed by in-development drugs such as proxalutamide and seviteronel.
Bicalutamide is marketed by AstraZeneca in oral tablet form under the brand names Casodex, Cosudex, Calutide, Calumid, and Kalumid in many countries. It is also marketed under the brand names Bicadex, Bical, Bicalox, Bicamide, Bicatlon, Bicusan, Binabic, Bypro, Calutol, and Ormandyl among others in various countries. The drug is sold under a large number of generic trade names such as Apo-Bicalutamide, Bicalutamide Accord, Bicalutamide Actavis, Bicalutamide Bluefish, Bicalutamide Kabi, Bicalutamide Sandoz, and Bicalutamide Teva as well. A combination formulation of bicalutamide and goserelin is marketed by AstraZeneca in Australia and New Zealand under the brand name ZolaCos-CP.
Cost and generics
Bicalutamide is off-patent and available as a generic. Unlike bicalutamide, the newer NSAA enzalutamide is still on-patent, and for this reason, is considerably more expensive in comparison.
The patent protection of all three of the first-generation NSAAs has expired and flutamide and bicalutamide are both available as low-cost generics. Nilutamide, on the other hand, has always been a poor third competitor to flutamide and bicalutamide and, in relation to this fact, has not been developed as a generic and is only available as brand name Nilandron, at least in the U.S.
Bicalutamide is considerably less costly than GnRH analogues, which, in spite of some having been off-patent many years, have been reported (in 2013) to typically cost US$10,000–$15,000 per year (or about US$1,000 per month) of treatment.
Sales and usage
Sales of bicalutamide (as Casodex) worldwide peaked at US$1.3 billion in 2007, and it has been described as a "billion-dollar-a-year" drug prior to losing its patent protection starting in 2007. In 2014, despite the introduction of abiraterone acetate in 2011 and enzalutamide in 2012, bicalutamide was still the most commonly prescribed drug in the treatment of metastatic castration-resistant prostate cancer (mCRPC). Moreover, in spite of being off-patent, bicalutamide was said to still generate a few hundred million dollars in sales per year for AstraZeneca. Total worldwide sales of brand name Casodex were approximately US$13.4 billion as of the end of 2018.[excessive citations]
Worldwide sales (millions, USD) of Casodex, 1995–2018
Between January 2007 and December 2009 (a period of three years), 1,232,143 prescriptions of bicalutamide were dispensed in the U.S., or about 400,000 prescriptions per year. During that time, bicalutamide accounted for about 87.2% of the NSAA market, while flutamide accounted for 10.5% of it and nilutamide for 2.3% of it. Approximately 96% of bicalutamide prescriptions were written for diagnosis codes that clearly indicated neoplasm. About 1,200, or 0.1% of bicalutamide prescriptions were dispensed to pediatric patients (age 0–16).
Bicalutamide has been studied in the treatment of benign prostatic hyperplasia (BPH) in a 24-week trial of 15 patients at a dosage of 50 mg/day. Prostate volume decreased by 26% in patients taking bicalutamide and urinary irritative symptom scores significantly decreased. Conversely, peak urine flow rates and urine pressure flow examinations were not significantly different between bicalutamide and placebo. The decrease in prostate volume achieved with bicalutamide was comparable to that observed with the 5α-reductase inhibitor finasteride, which is approved for the treatment of BPH. Breast tenderness (93%), gynecomastia (54%), and sexual dysfunction (60%) were all reported as side effects of bicalutamide at the dosage used in the study, although no treatment discontinuations due to adverse effects occurred and sexual functioning was maintained in 75% of patients.
Antiandrogens have been suggested for treating COVID-19 in men and as of May 2020 high-dose bicalutamide is in a phase II clinical trial for this purpose.
Bicalutamide may be used to treat hyperandrogenism and associated benign prostatic hyperplasia secondary to hyperadrenocorticism (caused by excessive adrenal androgens) in male ferrets. However, it has not been formally assessed in controlled studies for this purpose.
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^ abcdeChabner BA, Longo DL (8 November 2010). Cancer Chemotherapy and Biotherapy: Principles and Practice. Lippincott Williams & Wilkins. pp. 679–680. ISBN978-1-60547-431-1. From a structural standpoint, antiandrogens are classified as steroidal, including cyproterone [acetate] (Androcur) and megestrol [acetate], or nonsteroidal, including flutamide (Eulexin, others), bicalutamide (Casodex), and nilutamide (Nilandron). The steroidal antiandrogens are rarely used.
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^Higano CS (2012). "Sexuality and intimacy after definitive treatment and subsequent androgen deprivation therapy for prostate cancer". Journal of Clinical Oncology. 30 (30): 3720–5. doi:10.1200/JCO.2012.41.8509. PMID23008326.
^ abcdefKolvenbag GJ, Blackledge GR (January 1996). "Worldwide activity and safety of bicalutamide: a summary review". Urology. 47 (1A Suppl): 70–9, discussion 80–4. doi:10.1016/s0090-4295(96)80012-4. PMID8560681. Bicalutamide is a new antiandrogen that offers the convenience of once-daily administration, demonstrated activity in prostate cancer, and an excellent safety profile. Because it is effective and offers better tolerability than flutamide, bicalutamide represents a valid first choice for antiandrogen therapy in combination with castration for the treatment of patients with advanced prostate cancer.
^See WA, Wirth MP, McLeod DG, Iversen P, Klimberg I, Gleason D, et al. (August 2002). "Bicalutamide as immediate therapy either alone or as adjuvant to standard care of patients with localized or locally advanced prostate cancer: first analysis of the early prostate cancer program". The Journal of Urology. 168 (2): 429–35. doi:10.1016/S0022-5347(05)64652-6. PMID12131282.
^Iversen P, Johansson JE, Lodding P, Lukkarinen O, Lundmo P, Klarskov P, Tammela TL, Tasdemir I, Morris T, Carroll K (November 2004). "Bicalutamide (150 mg) versus placebo as immediate therapy alone or as adjuvant to therapy with curative intent for early nonmetastatic prostate cancer: 5.3-year median followup from the Scandinavian Prostate Cancer Group Study Number 6". The Journal of Urology. 172 (5 Pt 1): 1871–6. doi:10.1097/01.ju.0000139719.99825.54. PMID15540741.
^Iversen P, Johansson JE, Lodding P, Kylmälä T, Lundmo P, Klarskov P, Tammela TL, Tasdemir I, Morris T, Armstrong J (2006). "Bicalutamide 150 mg in addition to standard care for patients with early non-metastatic prostate cancer: updated results from the Scandinavian Prostate Cancer Period Group-6 Study after a median follow-up period of 7.1 years". Scandinavian Journal of Urology and Nephrology. 40 (6): 441–52. doi:10.1080/00365590601017329. PMID17130095. S2CID25862814.
^Foster WR, Car BD, Shi H, Levesque PC, Obermeier MT, Gan J, Arezzo JC, Powlin SS, Dinchuk JE, Balog A, Salvati ME, Attar RM, Gottardis MM (2011). "Drug safety is a barrier to the discovery and development of new androgen receptor antagonists". Prostate. 71 (5): 480–8. doi:10.1002/pros.21263. PMID20878947. S2CID24620044.
^Bahceci M, Tuzcu A, Canoruc N, Tuzun Y, Kidir V, Aslan C (2004). "Serum C-reactive protein (CRP) levels and insulin resistance in non-obese women with polycystic ovarian syndrome, and effect of bicalutamide on hirsutism, CRP levels and insulin resistance". Hormone Research. 62 (6): 283–7. doi:10.1159/000081973. PMID15542929. S2CID46261843.
^Genrx (1999). 1999 Mosby's GenRx. Mosby. ISBN978-0-323-00625-5. A 79-year-old man attempted suicide by ingesting 13g of nilutamide (i.e., 43 times the maximum recommended dose). Despite immediate gastric lavage and oral administration of activated charcoal, plasma nilutamide levels peaked at 6 times the normal range 2 hours after ingestion. There were no clinical signs or symptoms or changes in parameters such as transaminases or chest x-ray. Maintenance treatment (150 mg/day) was resumed 30 days later.
^ abcdefghiWeber GF (22 July 2015). Molecular Therapies of Cancer. Springer. pp. 318–. ISBN978-3-319-13278-5. Compared to flutamide and nilutamide, bicalutamide has a 2-fold increased affinity for the Androgen Receptor, a longer half-life, and substantially reduced toxicities. Based on a more favorable safety profile relative to flutamide, bicalutamide is indicated for use in combination therapy with a Gonadotropin Releasing Hormone analog for the treatment of advanced metastatic prostate carcinoma.
^Eri LM, Haug E, Tveter KJ (March 1995). "Effects on the endocrine system of long-term treatment with the non-steroidal anti-androgen Casodex in patients with benign prostatic hyperplasia". British Journal of Urology. 75 (3): 335–40. doi:10.1111/j.1464-410X.1995.tb07345.x. PMID7537602.
^ abBouchard P, Caraty A (15 November 1993). GnRH, GnRH Analogs, Gonadotropins and Gonadal Peptides. CRC Press. pp. 455–456. ISBN978-0-203-09205-7. [...] when male levels of androgens are achieved in plasma, their effects on gonadotropin secretion are similar in women and men. [...] administration of flutamide in a group of normally-cycling women produced a clinical improvement of acne and hirsutism without any significant hormonal change. [...] All these data emphasize that physiological levels of androgens have no action on the regulation of gonadotropins in normal women. [...] Androgens do not directly play a role in gonadotropin regulation [in women].
^Asscheman H, Gooren LJ, Peereboom-Wynia JD (1989). "Reduction in undesired sexual hair growth with anandron in male-to-female transsexuals—experiences with a novel androgen receptor blocker". Clinical and Experimental Dermatology. 14 (5): 361–3. doi:10.1111/j.1365-2230.1989.tb02585.x. PMID2612040. S2CID45303518.
^ abWibowo E, Schellhammer P, Wassersug RJ (January 2011). "Role of estrogen in normal male function: clinical implications for patients with prostate cancer on androgen deprivation therapy". The Journal of Urology. 185 (1): 17–23. doi:10.1016/j.juro.2010.08.094. PMID21074215.
^ abMotofei IG, Rowland DL, Popa F, Kreienkamp D, Paunica S (July 2011). "Preliminary study with bicalutamide in heterosexual and homosexual patients with prostate cancer: a possible implication of androgens in male homosexual arousal". BJU International. 108 (1): 110–5. doi:10.1111/j.1464-410X.2010.09764.x. PMID20955264. S2CID45482984.
^ abWibowo E, Wassersug RJ (September 2013). "The effect of estrogen on the sexual interest of castrated males: Implications to prostate cancer patients on androgen-deprivation therapy". Critical Reviews in Oncology/Hematology. 87 (3): 224–38. doi:10.1016/j.critrevonc.2013.01.006. PMID23484454.
^ abKanhai RC, Hage JJ, van Diest PJ, Bloemena E, Mulder JW (January 2000). "Short-term and long-term histologic effects of castration and estrogen treatment on breast tissue of 14 male-to-female transsexuals in comparison with two chemically castrated men". The American Journal of Surgical Pathology. 24 (1): 74–80. doi:10.1097/00000478-200001000-00009. PMID10632490.
^Morgante E, Gradini R, Realacci M, Sale P, D'Eramo G, Perrone GA, Cardillo MR, Petrangeli E, Russo M, Di Silverio F (March 2001). "Effects of long-term treatment with the anti-androgen bicalutamide on human testis: an ultrastructural and morphometric study". Histopathology. 38 (3): 195–201. doi:10.1046/j.1365-2559.2001.01077.x. PMID11260298. S2CID36892099.
^ abJones CA, Reiter L, Greenblatt E (2016). "Fertility preservation in transgender patients". International Journal of Transgenderism. 17 (2): 76–82. doi:10.1080/15532739.2016.1153992. ISSN1553-2739. S2CID58849546. Traditionally, patients have been advised to cryopreserve sperm prior to starting cross-sex hormone therapy as there is a potential for a decline in sperm motility with high-dose estrogen therapy over time (Lubbert et al., 1992). However, this decline in fertility due to estrogen therapy is controversial due to limited studies.
^ abPayne AH, Hardy MP (28 October 2007). The Leydig Cell in Health and Disease. Springer Science & Business Media. pp. 422–431. ISBN978-1-59745-453-7. Estrogens are highly efficient inhibitors of the hypothalamic-hypophyseal-testicular axis (212–214). Aside from their negative feedback action at the level of the hypothalamus and pituitary, direct inhibitory effects on the testis are likely (215,216). [...] The histology of the testes [with estrogen treatment] showed disorganization of the seminiferous tubules, vacuolization and absence of lumen, and compartmentalization of spermatogenesis.
^ abNeumann F (1994). "The antiandrogen cyproterone acetate: discovery, chemistry, basic pharmacology, clinical use and tool in basic research". Exp. Clin. Endocrinol. 102 (1): 1–32. doi:10.1055/s-0029-1211261. PMID8005205. Spermatogenesis is also androgen-dependent and is inhibited by CPA, meaning that patients treated with high doses of CPA are sterile (Figure 23). All the effects of CPA are fully reversible.
^ abSalam MA (2003). Principles & Practice of Urology: A Comprehensive Text. Universal-Publishers. pp. 684–. ISBN978-1-58112-412-5. Estrogens act primarily through negative feedback at the hypothalamic-pituitary level to reduce LH secretion and testicular androgen synthesis. [...] Interestingly, if the treatment with estrogens is discontinued after 3 yr. of uninterrupted exposure, serum testosterone may remain at castration levels for up to another 3 yr. This prolonged suppression is thought to result from a direct effect of estrogens on the Leydig cells.
^ abFoster WR, Car BD, Shi H, Levesque PC, Obermeier MT, Gan J, Arezzo JC, Powlin SS, Dinchuk JE, Balog A, Salvati ME, Attar RM, Gottardis MM (April 2011). "Drug safety is a barrier to the discovery and development of new androgen receptor antagonists". The Prostate. 71 (5): 480–8. doi:10.1002/pros.21263. PMID20878947. S2CID24620044.
^Furr BJ, Valcaccia B, Curry B, Woodburn JR, Chesterson G, Tucker H (June 1987). "ICI 176,334: a novel non-steroidal, peripherally selective antiandrogen". The Journal of Endocrinology. 113 (3): R7-9. doi:10.1677/joe.0.113R007. PMID3625091.
^Soloway MS, Schellhammer PF, Smith JA, Chodak GW, Vogelzang NJ, Kennealey GT (December 1995). "Bicalutamide in the treatment of advanced prostatic carcinoma: a phase II noncomparative multicenter trial evaluating safety, efficacy and long-term endocrine effects of monotherapy". The Journal of Urology. 154 (6): 2110–4. doi:10.1016/S0022-5347(01)66709-0. PMID7500470.
^Mason M (August 2006). "What implications do the tolerability profiles of antiandrogens and other commonly used prostate cancer treatments have on patient care?". Journal of Cancer Research and Clinical Oncology. 132 Suppl 1: S27-35. doi:10.1007/s00432-006-0134-4. PMID16896883. S2CID19685819.
^Fradet Y (February 2004). "Bicalutamide (Casodex) in the treatment of prostate cancer". Expert Review of Anticancer Therapy. 4 (1): 37–48. doi:10.1586/1473722.214.171.124. PMID14748655. S2CID34153031. In contrast, the incidence of diarrhea was comparable between the bicalutamide and placebo groups (6.3 vs. 6.4%, respectively) in the EPC program .
^Sharma K, Pawar GV, Giri S, Rajagopal S, Mullangi R (2012). "Development and validation of a highly sensitive LC-MS/MS-ESI method for the determination of bicalutamide in mouse plasma: application to a pharmacokinetic study". Biomedical Chromatography. 26 (12): 1589–95. doi:10.1002/bmc.2736. PMID22495777.
^Anderson PO, Knoben JE, Troutman WG (22 August 2001). Handbook of Clinical Drug Data. Canadian Medical Association Journal. 128. McGraw Hill Professional. p. 245. ISBN978-0-07-138942-6. PMC1875767. PMID20313924. With an oral dose of 50 mg/day, bicalutamide attains a peak serum level of 8.9 mg/L (21 μmol/L) 31 hr after a dose at steady state. CI of (R)-bicalutamide is 0.32 L/hr. The active (R)-enantiomer of bicalutamide is oxidized to an inactive metabolite, which, like the inactive (S)-enantiomer, is glucuronidated and cleared rapidly by elimination in the urine and feces.165
^ abcdeMohler ML, Bohl CE, Jones A, Coss CC, Narayanan R, He Y, Hwang DJ, Dalton JT, Miller DD (June 2009). "Nonsteroidal selective androgen receptor modulators (SARMs): dissociating the anabolic and androgenic activities of the androgen receptor for therapeutic benefit". Journal of Medicinal Chemistry. 52 (12): 3597–617. doi:10.1021/jm900280m. PMID19432422. [C]linically relevant antiandrogens currently are nonsteroidal anilide derivatives. Antiandrogens used for prostate cancer include the monoarylpropionamide flutamide (1) (a prodrug of hydroxyflutamide (2)),29–31 the hydantoin nilutamide(3),32–34 and the diarylpropionamide bicalutamide (4) (Chart1).35–37
^ abcSegal S, Narayanan R, Dalton JT (April 2006). "Therapeutic potential of the SARMs: revisiting the androgen receptor for drug discovery". Expert Opinion on Investigational Drugs. 15 (4): 377–87. doi:10.1517/135437126.96.36.1997. PMID16548787. S2CID31787187. Structural modifications of bicalutamide led to the discovery of the first nonsteroidal androgens (the aryl propionamides) in 1998. Lead compounds in this class (denoted S1 and S4 in published literature) not only bind to the AR with high affinity (low nanomolar range), but also demonstrate tissue selectivity in animal models [46,50].
^ abcdParent EE, Dence CS, Jenks C, Sharp TL, Welch MJ, Katzenellenbogen JA (2007). "Synthesis and biological evaluation of [18F]bicalutamide, 4-[76Br]bromobicalutamide, and 4-[76Br]bromo-thiobicalutamide as non-steroidal androgens for prostate cancer imaging". J. Med. Chem. 50 (5): 1028–40. doi:10.1021/jm060847r. PMID17328524.
^ abcTucker H, Crook JW, Chesterson GJ (1988). "Nonsteroidal antiandrogens. Synthesis and structure-activity relationships of 3-substituted derivatives of 2-hydroxypropionanilides". Journal of Medicinal Chemistry. 31 (5): 954–9. doi:10.1021/jm00400a011. PMID3361581.
^James KD, Ekwuribe NN (2002). "A Two-step Synthesis of the Anti-cancer Drug (R,S)-Bicalutamide". Synthesis. 2002 (7): 850–2. doi:10.1055/s-2002-28508.
^US application 2006/0041161, Pizzetti E, Vigano E, Lussana M, Landonio E, "Procedure for the synthesis of bicalutamide", published 23 February 2006
^Chand M, Shukla AK (2012). Novel Synthesis of Bicalutamide Drug Substance and their Impurities using Imidazolium Type of Ionic Liquid (Report). doi:10.2139/ssrn.2160199. SSRN2160199.
^Diamanti-Kandarakis E (September 1999). "Current aspects of antiandrogen therapy in women". Current Pharmaceutical Design. 5 (9): 707–23. PMID10495361. Several trials demonstrated complete clearing of acne with flutamide [62,77]. Flutamide used in combination with an [oral contraceptive], at a dose of 500mg/d, flutamide caused a dramatic decrease (80%) in total acne, seborrhea and hair loss score after only 3 months of therapy . When used as a monotherapy in lean and obese PCOS, it significantly improves the signs of hyperandrogenism, hirsutism and particularly acne . [...] flutamide 500mg/d combined with an [oral contraceptive] caused an increase in cosmetically acceptable hair density, in sex of seven women suffering from diffuse androgenetic alopecia .
^Furr BJ, Valcaccia B, Curry B, Woodburn JR, Chesterson G, Tucker H (June 1987). "ICI 176,334: a novel non-steroidal, peripherally selective antiandrogen". The Journal of Endocrinology. 113 (3): R7-9. doi:10.1677/joe.0.113r007. PMID3625091.
^Newling DW (1990). "The response of advanced prostatic cancer to a new non-steroidal antiandrogen: results of a multicenter open phase II study of Casodex. European/Australian Co-operative Group". European Urology. 18 Suppl 3: 18–21. doi:10.1159/000463973. PMID2094607.
^Bono AV (2004). "Overview of Current Treatment Strategies in Prostate Cancer". European Urology Supplements. 3 (1): 2–7. doi:10.1016/j.eursup.2003.12.002. The Canadian Health Authorities have withdrawn the approval for antiandrogen monotherapy with bicalutamide for the treatment of localised prostate cancer . Several European countries have also withdrawn approval for bicalutamide for this indication.
^Nargund VH, Raghavan D, Sandler HM (17 January 2015). Urological Oncology. Springer. pp. 823–. ISBN978-0-85729-482-1. On the other hand, the 150 mg dose of bicalutamide has been associated with some safety concerns, such as a higher death rate when added to active surveillance in the early prostate cancer trialists group study , which has led the United States and Canada to recommend against prescribing the 150 mg dose .
^Wang LG, Mencher SK, McCarron JP, Ferrari AC (2004). "The biological basis for the use of an anti-androgen and a 5-alpha-reductase inhibitor in the treatment of recurrent prostate cancer: Case report and review". Oncology Reports. 11 (6): 1325–9. doi:10.3892/or.11.6.1325. PMID15138573.
^Merrick GS, Butler WM, Wallner KE, Galbreath RW, Allen ZA, Kurko B (2006). "Efficacy of neoadjuvant bicalutamide and dutasteride as a cytoreductive regimen before prostate brachytherapy". Urology. 68 (1): 116–20. doi:10.1016/j.urology.2006.01.061. PMID16844453.
^Sartor O, Gomella LG, Gagnier P, Melich K, Dann R (2009). "Dutasteride and bicalutamide in patients with hormone-refractory prostate cancer: the Therapy Assessed by Rising PSA (TARP) study rationale and design". The Canadian Journal of Urology. 16 (5): 4806–12. PMID19796455.
^Chu FM, Sartor O, Gomella L, Rudo T, Somerville MC, Hereghty B, Manyak MJ (2015). "A randomised, double-blind study comparing the addition of bicalutamide with or without dutasteride to GnRH analogue therapy in men with non-metastatic castrate-resistant prostate cancer". European Journal of Cancer. 51 (12): 1555–69. doi:10.1016/j.ejca.2015.04.028. PMID26048455.
^Gaudet M, Vigneault É, Foster W, Meyer F, Martin AG (2016). "Randomized non-inferiority trial of Bicalutamide and Dutasteride versus LHRH agonists for prostate volume reduction prior to I-125 permanent implant brachytherapy for prostate cancer". Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology. 118 (1): 141–7. doi:10.1016/j.radonc.2015.11.022. PMID26702991.
^Ho, Thai H.; Nunez-Nateras, Rafael; Hou, Yue-Xian; Bryce, Alan H.; Northfelt, Donald W.; Dueck, Amylou C.; Wong, Bryan; Stanton, Melissa L.; Joseph, Richard W.; Castle, Erik P. (2017). "A Study of Combination Bicalutamide and Raloxifene for Patients With Castration-Resistant Prostate Cancer". Clinical Genitourinary Cancer. 15 (2): 196–202.e1. doi:10.1016/j.clgc.2016.08.026. ISSN1558-7673. PMID27771244. S2CID19043552.
^ abcdLepor H (1993). "Medical therapy for benign prostatic hyperplasia". Urology. 42 (5): 483–501. doi:10.1016/0090-4295(93)90258-c. PMID7694413. The clinically significant adverse events reported in the casodex group included breast tenderness (93%), breast enlargement (54%), and sexual dysfunction (60%). In none of the patients in the placebo group did any of these adverse events develop. None of the subjects discontinued therapy owing to an adverse event.
^Fox JG, Marini RP (26 March 2014). Biology and Diseases of the Ferret. Wiley. p. 980. ISBN978-1-118-78273-6. Other agents have been proposed for medical management of [adrenal-associated endocrinopathy] but have not been studied. Possibly medications include the androgen receptor blockers flutamide and bicalutamide, the anti-androgen finasteride, estrogen-inhibiting anastrozole, and another GnRH analog, goserelin. [...] None of these drugs have been tested in controlled clinical trials in ferrets.
Furr BJ, Tucker H (January 1996). "The preclinical development of bicalutamide: pharmacodynamics and mechanism of action". Urology. 47 (1A Suppl): 13–25, discussion 29–32. doi:10.1016/S0090-4295(96)80003-3. PMID8560673.