Description
Tadalis SX (tadalafil)
Tadalis SX is a 20 mg tadalafil manufactured by Ajanta Pharma in India. Tadalafil has an approved indication beyond erectile dysfunction — it’s also used at lower daily doses for benign prostatic hyperplasia (BPH) and pulmonary arterial hypertension. Tadalis SX at 20 mg is the on-demand ED formulation, but the broader licensed use of tadalafil reflects that the drug’s mechanism — PDE5 inhibition — has applications in other smooth muscle tissue beyond penile vasculature.
Dosing
For irregular or occasional use: 20 mg taken at least 30 minutes before sexual activity. For men with frequent sexual activity or those who prefer not to plan around a dosing window: 5 mg daily, taken at the same time each day regardless of activity. Duration of on-demand effect: up to 36 hours.
Tadalafil absorption is relatively unaffected by food — including high-fat meals — which distinguishes it from sildenafil. Alcohol doesn’t significantly alter tadalafil’s pharmacokinetics either, though the vasodilatory and blood-pressure-lowering effects of both are additive. Moderate alcohol intake is the practical limit.
Nitrates
Tadalafil combined with nitrates — nitroglycerin, isosorbide preparations, recreational nitrites — causes severe and potentially fatal hypotension. This is absolute, applies to both on-demand and daily dosing, and cannot be made safe by adjusting the dose or timing.
CYP3A4 interactions
Tadalafil is metabolized by CYP3A4. Erythromycin and other CYP3A4 inhibitors (ketoconazole, ritonavir) slow tadalafil metabolism and raise blood levels — this increases exposure and side effect risk. Rifampicin, by contrast, is a potent CYP3A4 inducer: it accelerates tadalafil metabolism and reduces blood levels, potentially making the drug less effective, not more. Co-administration with other ED medications on the same day is contraindicated.
Contraindications
All nitrates and nitrites. Heart failure. Stroke within the past 6 months. Peyronie’s disease. Retinitis pigmentosa. History of NAION. Severe renal or hepatic impairment. Allergy to tadalafil or lactose (tablets contain lactose). Gastric or duodenal ulcers.
Side effects
Myalgia, headache, nausea, diarrhea, facial flushing, and blood pressure drops are the most commonly reported. Back and muscle pain are characteristic of tadalafil and typically appear several hours after dosing, resolving without treatment.
Chest or arm pain, facial swelling, and skin hives require immediate evaluation.
Priapism — erection lasting more than 4 hours — is a medical emergency. Permanent damage to erectile tissue occurs without prompt treatment.
