Methyltestosterone 25 mg

Methyltestosterone 25 mg (Methyltestosterone) · ATC G03BA02

Androgen · oral 17α-methylated

Each tablet contains Methyltestosterone 25 mg.

For the full list of excipients, see section 6.1.

Tablet for oral administration.

Therapeutic indications

Androgen replacement therapy where an oral route is preferred, as determined by a physician.

Posology and method of administration

Take orally as directed by a physician. Swallow whole with water. Do not exceed the prescribed dose.

Contraindications

Known hypersensitivity to the active substance or excipients. Known or suspected carcinoma of the prostate or male breast. Not for use in women, in pregnancy or while breastfeeding. Use with caution in cardiac, renal or hepatic impairment.

Special warnings and precautions for use

Keep out of the reach and sight of children. Contains a substance prohibited in sport (WADA).

Interaction with other medicinal products

Coumarin anticoagulants

Anticoagulant response is potentiated with prolongation of prothrombin time and risk of bleeding; frequent INR monitoring and dose reduction are necessary.

Insulin and oral antidiabetic agents

Androgens may lower blood glucose and reduce insulin requirements; glycaemic control should be monitored and antidiabetic therapy adjusted.

Ciclosporin and tacrolimus

Inhibition of hepatic metabolism raises calcineurin inhibitor concentrations, increasing the risk of nephrotoxicity and other toxicity.

Corticosteroids and corticotrophin

Additive sodium and water retention, increasing the risk of oedema, particularly with cardiac or hepatic disease.

Oxyphenbutazone, and other hepatically metabolised or hepatotoxic agents including alcohol

Serum oxyphenbutazone concentrations may rise; concurrent hepatotoxins increase the risk of cholestatic and hepatocellular injury.

Use in special populations

Pregnancy and breastfeeding

Contraindicated. Androgens cross the placenta and can virilise a female foetus; treatment is also inappropriate during breastfeeding. Women of childbearing potential must use effective contraception.

Paediatric population

Use in boys with constitutionally delayed puberty only under specialist supervision, with radiological monitoring of bone age every six months, because androgens can accelerate epiphyseal maturation and compromise final adult height.

Elderly

Elderly men are at increased risk of prostatic hyperplasia and occult prostatic carcinoma, urinary obstruction, polycythaemia and fluid retention; prostate examination, prostate-specific antigen and haematocrit should be checked before and during treatment.

Hepatic impairment

Contraindicated in significant hepatic impairment or hepatic tumours. As a 17alpha-alkylated androgen it carries a definite risk of cholestasis and peliosis hepatis; liver function must be monitored and the product withdrawn if jaundice develops.

Renal impairment and cardiac failure

Fluid and electrolyte retention may precipitate oedema or cardiac decompensation; use with caution and monitor weight, blood pressure and serum electrolytes.

Athletes

Methyltestosterone is prohibited in and out of competition as an exogenous anabolic androgenic steroid under class S1.1a of the WADA Prohibited List; administration will produce an adverse analytical finding in doping control.

Undesirable effects

Hepatobiliary disorders

Cholestatic hepatitis and jaundice, raised transaminases and alkaline phosphatase, peliosis hepatis, hepatic adenoma and, rarely, hepatocellular carcinoma with prolonged use

Reproductive system and breast disorders

Gynaecomastia, priapism and excessive sexual stimulation, oligospermia and testicular atrophy, prostatic enlargement and worsening of pre-existing prostatic carcinoma; in women, menstrual irregularity, amenorrhoea and clitoral enlargement

Endocrine disorders

Suppression of gonadotrophins and endogenous testosterone production, virilisation in women, decreased thyroxine-binding globulin with altered thyroid function test results

Investigations

Reduced HDL-cholesterol and raised LDL-cholesterol, polycythaemia with increased haematocrit, hypercalcaemia in patients with metastatic breast carcinoma

Skin and subcutaneous tissue disorders

Acne, seborrhoea, hirsutism, male-pattern baldness

Psychiatric disorders

Aggression, irritability, anxiety, mood disturbance, insomnia

Metabolism and nutrition disorders

Sodium, chloride, water and calcium retention with oedema and weight gain

Musculoskeletal and connective tissue disorders

Premature closure of the epiphyses in prepubertal patients

Overdose

Overdosage may present with nausea, vomiting, headache, oedema, gynaecomastia, priapism and, in women, acute virilisation; prolonged excessive exposure causes cholestatic jaundice and polycythaemia. There is no specific antidote and management is symptomatic and supportive, with withdrawal of the product and monitoring of liver function, haematocrit and electrolytes.

Pharmacodynamic properties

Methyltestosterone (ATC G03BA02) is the prototypical orally active androgen, testosterone bearing a 17alpha-methyl substituent. It binds the nuclear androgen receptor and, in some tissues after 5alpha-reduction to mestanolone (17alpha-methyldihydrotestosterone), reproduces the physiological actions of testosterone: development and maintenance of male secondary sexual characteristics, libido, nitrogen retention, erythropoiesis and maintenance of bone mineral density. It is a substrate for aromatase and is converted to 17alpha-methyloestradiol, a potent oestrogen that is poorly cleared, so oestrogenic effects such as gynaecomastia are comparatively common. Exogenous administration suppresses pituitary LH and FSH release, with consequent reduction of endogenous testosterone and spermatogenesis.

Pharmacokinetic properties

Absorption from the gastrointestinal tract is good and the 17alpha-methyl group protects the molecule from complete hepatic first-pass inactivation; buccal administration bypasses the portal circulation and yields substantially higher systemic exposure than the same swallowed dose. Plasma protein binding is high, though affinity for sex hormone binding globulin is much lower than that of testosterone. Metabolism is hepatic, involving 5alpha-reduction to mestanolone, aromatisation to 17alpha-methyloestradiol, ring-A reduction and hydroxylation, with subsequent glucuronide and sulphate conjugation; the 17alpha-methyl group blocks 17-oxidation. Excretion is mainly urinary as conjugates, and the plasma elimination half-life is short, in the region of 2.5 to 4 hours.

List of excipients

Lactose monohydrate, maize starch, pregelatinised maize starch, povidone K25, croscarmellose sodium, talc, magnesium stearate. Uncoated tablet. All excipients comply with the current Ph. Eur. or USP-NF monograph.

Excipient warnings

This medicine contains lactose monohydrate. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine. This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially sodium-free.

Incompatibilities

Not applicable.

Shelf life

36 months from the date of manufacture in the unopened container. Do not use after the expiry date printed on the carton and bottle label.

After first opening

After first opening of the bottle, use within 90 days. Replace the cap firmly after each withdrawal and keep the desiccant canister in the bottle; it protects the tablets from moisture and is not for consumption.

Storage

Store below 25 °C in a dry place. Keep tablets in the outer carton until use.

Container

White opaque high-density polyethylene (HDPE) bottle with an integral desiccant canister, closed with a tamper-evident, child-resistant polypropylene cap over an induction-sealed liner. Pack size: 100 uncoated tablets in one bottle per serialised carton, with the patient information leaflet, GS1 DataMatrix, human-readable serial and verification code.

Disposal

No special requirements for destruction. Any unused medicinal product or waste material should be disposed of in accordance with local requirements. Tablets must not be disposed of via wastewater or with household waste; unused tablets, part-used bottles and empty packaging should be returned to the point of supply for controlled disposal.

Pack

100 Tablets

GTIN

05012345678919

Serial

2185 9630 7418 19

LOT

MT2705E

MFG

07 / 2027

EXP

07 / 2030

Every carton carries a GS1 DataMatrix and a verification code; a pack can be checked at ergopharm.net/verify.

Ergopharm Advanced Research Centre, Tandalja, Vadodara, Gujarat 390012, India. For Export Only.

Report a suspected adverse reaction or quality defect to pv@ergopharm.net.