Viagra: Dosage Guidelines

Viagra is one of the most proven and most convenient drugs for erectile dysfunction treatment, the dosage of which may vary.

Which Dosage Do I Need?

viagra

The drug is taken orally.

Viagra pills should be taken 1 hour before sexual activity. For most patients, the recommended dosage of the drug is 50 mg. Considering efficacy and tolerability, the dosage can be increased to 100 mg or decreased to 25 mg. The dosage by weight is not adjusted.

The maximum Viagra dosage is 100 mg. The maximum recommended multiplicity of application is 1 time per day.

The dose for 35 years old and older patients requires no adjustment.

At mild to moderate renal insufficiency (creatinine clearance 30 – 80 ml/min) dosage adjustment is not required, at severe renal insufficiency (creatinine clearance) an average dose should be reduced to 25 mg. The maximum dose for pulmonary hypertension is not determined, dosage regimen is chosen for each patient individually.

Since sildenafil clearance in patients with liver damage (e. g., at cirrhosis), the normal dosage should be reduced to 25 mg.

Combined Use with Other Drugs

When combined with ritonavir, the maximal Viagra dosage should not exceed 25 mg, multiplicity of application – 1 time in 48 hours.

In the case of a joint application with CYP3A4 isoenzyme inhibitors (erythromycin, saquinavir, ketoconazole, itraconazole), the initial dose of sildenafil should be 25 mg.

To minimize the risk of postural hypotension in patients taking alpha-blockers, Viagra pills should be taken only after hemodynamic stabilization is achieved in these patients. Reasonability initial dosage of sildenafil reduction should be considered.

Viagra Overdose: Symptoms and Treatment

At a single dose of 800 mg, adverse events were comparable to those when taking sildenafil at lower doses, but were more frequent.

In case of Viagra overdose, the chances of side effects sharply increase.

Symptoms:

  • skin hypersensitivity (including skin rash);
  • tachycardia, decreased blood pressure, fainting;
  • vomiting;
  • red eyes, pain in the eyes;
  • prolonged or painful erection (priapism).

Treatment: symptomatic therapy. Hemodialysis does not accelerate sildenafil clearance, as the latter actively binds to plasma proteins and is excreted in urine.