Does cimetidine (Tagamet) affect sex drive in men, women, or both?

Cimetidine and Sex Drive Effects

Cimetidine (Tagamet) affects sex drive primarily in men, not women, through its antiandrogenic properties and disruption of sex hormone metabolism.

Primary Effects in Men

Cimetidine causes sexual dysfunction in men through multiple mechanisms:

Antiandrogenic Activity

• Cimetidine directly blocks androgen receptors by competitively inhibiting dihydrotestosterone (DHT) binding to cytoplasmic receptors in androgen-sensitive tissues 1
• This antiandrogenic effect reduces prostate and seminal vesicle weights in animal studies, demonstrating clinically relevant androgen blockade 1

Testosterone Synthesis Disruption

• Cimetidine can block testosterone synthesis by causing a reversible defect in 17-beta-hydroxysteroid dehydrogenase, resulting in low testosterone levels and sexual dysfunction 2
• Case reports document men developing sexual dysfunction with low testosterone levels that normalized after discontinuing cimetidine 2

Estrogen Metabolism Interference

• Cimetidine reduces estradiol 2-hydroxylation by approximately 38% (from 31.7% to 19.7%), leading to increased serum estradiol concentrations by about 20% 3
• This creates a relative estrogen excess state in men, contributing to gynecomastia and sexual dysfunction 3
• This effect occurs at standard doses (800 mg twice daily) and even at lower doses (400 mg twice daily) 3

Clinical Manifestations in Men

• Reversible impotence occurs particularly in men with pathological hypersecretory states (e.g., Zollinger-Ellison Syndrome) receiving high doses for ≥12 months 4
• Gynecomastia develops in approximately 4% of men treated for pathological hypersecretory states and 0.3-1% in other patients treated for ≥1 month 4
• Reduced sperm count (43% mean reduction) occurs after 9 weeks of therapy at 1200 mg/day 5
• Decreased libido is listed as a common adverse effect 6

Effects in Women

No evidence exists that cimetidine affects sex drive in women. The available literature focuses exclusively on male sexual dysfunction, and the drug's mechanism of action (antiandrogenic effects, testosterone synthesis blockade) would not be expected to reduce libido in women 4, 2, 1, 3.

Important Clinical Considerations

Drug Interactions Relevant to Sexual Function

• Cimetidine can cause clinically significant pharmacokinetic interactions with medications used to treat sexual dysfunction, including tricyclic antidepressants used for premature ejaculation 6
• These interactions occur through cytochrome P450 enzyme inhibition and plasma protein binding competition 6

Reversibility

• Sexual dysfunction and hormonal changes are typically reversible within 3-4 days of discontinuation 2
• Gynecomastia may persist longer but often resolves with continued treatment or after stopping the drug 4

Alternative H2-Blocker

• Ranitidine does not affect estradiol metabolism and represents a safer alternative for men concerned about sexual side effects 3