Tadalafil vs Famotidine: side-by-side comparison
Tadalafil (PDE5 inhibitor) and Famotidine (H2-receptor antagonist) belong to different therapeutic classes and are rarely substitutes for each other. The comparison is useful when a single patient is weighing both options for adjacent or overlapping needs.
| Property | Tadalafil | Famotidine |
|---|---|---|
| Therapeutic class | PDE5 inhibitor | H2-receptor antagonist |
| CAS | 171596-29-5 | 76824-35-6 |
| ATC | G04BE08 | A02BA03 |
| Molecular weight | 389.4 g/mol | 337.45 g/mol |
| Brands with this active ingredient | 7 | 1 |
What they share
Tadalafil and Famotidine share the common regulatory framework for prescription active ingredients, bioequivalence standards for generics, and pharmacist oversight. Beyond that, points in common are limited.
Key differences
Tadalafil acts by a different mechanism than Famotidine, with indications that barely overlap. Comparing the two is useful when a clinician has mentioned both in the same context or the patient wants to understand why one was prescribed instead of the other.
Mechanisms compared
Tadalafil: Tadalafil selectively inhibits PDE5, the enzyme responsible for breaking down cyclic guanosine monophosphate in the corpus cavernosum and other vascular smooth muscle. Famotidine: Famotidine reversibly and competitively blocks histamine H2 receptors on gastric parietal cells, reducing both basal and stimulated gastric acid secretion.
Indications compared
Tadalafil: Tadalafil is approved for three indications: erectile dysfunction in adult men, lower urinary tract symptoms associated with benign prostatic hyperplasia, and pulmonary arterial hypertension. Famotidine: Famotidine is approved in adults and children for short-term treatment of active duodenal and gastric ulcer, maintenance therapy of duodenal ulcer, gastro-oesophageal reflux disease, Zollinger-Ellison syndrome and other…
Safety profile
Tadalafil: Common adverse effects in clinical trials include headache, dyspepsia, back pain, myalgia, nasal congestion and facial flushing. Famotidine: Famotidine is generally well tolerated.
Frequently asked questions
Is Tadalafil better than Famotidine? ▾
Tadalafil and Famotidine are not "better or worse" — they treat different things. The sensible question is which fits your specific need.
Can Tadalafil and Famotidine be combined? ▾
Whether they can be combined depends on the indications and the interaction profile of each. If both are in a single prescription, the prescriber has weighed it; in self-medication they should never be combined.
Do they have the same side-effect profile? ▾
No — they belong to different classes and have distinct side-effect profiles. Each has its own prescribing information.
Products with Tadalafil
Products with Famotidine
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.