Skip navigation
MedlinePlus Logo

Generic Cialis


Generic Cialis. Common Adverse Effects

Interactions for Cialis

Metabolized principally by CYP3A4. Will not may actually induce or inhibit the clearance of other drugs metabolized by CYP isoforms 1A2, 3A4, 2C9, 2C19, 2D6, or 2E1.

Drugs Affecting Hepatic or Metabolized by Hepatic Microsomal Enzymes

Potent inhibitors of CYP3A4: Potential pharmacokinetic interaction (increased tadalafil exposure) and increased risk of PDE type 5 inhibitor-associated adverse effects (e.g., hypotension, syncope, visual changes, priapism).When used concomitantly in patients with BPH and/or ED, will not exceed tadalafil dosage of 2.5 mg once daily; avoid concomitant use of tadalafil (Adcirca) with potent CYP3A inhibitors (with exception of ritonavir). (See Specific Drugs and Foods under Interactions.) Potent inducers of CYP3A: Potential pharmacokinetic interaction (decreased tadalafil exposure) and possible decreased efficacy of tadalafil. No dosage adjustment warranted in patients with BPH and/or ED; avoid concomitant utilization of tadalafil (Adcirca) with potent CYP3A inducers.

Specific Drugs and Foods

Drug or Food Interaction Comments
α-Adrenergic blocking agents Possible symptomatic hypotension Patients with ED: In people who find themselves stable on an α-adrenergic blocker, initiate tadalafil at lowest recommended dosage; in those currently receiving tadalafil, initiate α-adrenergic blocker at the smallest recommended dosage Patients with BPH: Concomitant use not suggested; in patients already receiving an α-adrenergic blocker, discontinue such therapy >1 day previous to initiating tadalafil
Alcohol Possible additive hypotensive effects with heavy alcohol ingestion (e.g., >180 mL of 80 proof vodka) Avoid alcohol excessively (e.g., >5 glasses of wine or shots of whiskey)
Ambrisentan Clinically important pharmacokinetic interaction not observed No dosage adjustments necessary
Amlodipine Possible additive hypotensive effects
Antacids (aluminum and magnesium hydroxide) Possible delayed absorption of tadalafil
Anticonvulsants (carbamazepine, phenytoin, phenobarbital) Possible decreased exposure of tadalafil and decreased effectiveness of once-daily tadalafil Tadalafil for BPH and/or ED: No dosage adjustments recommended Tadalafil for PAH: Avoid concomitant use
Antifungal agents, azole (i.e., itraconazole, ketoconazole) Possible increased AUC and peak plasma concentrations of tadalafil As-needed tadalafil for ED: Maximum dosage 10 mg once every 72 hours Once-daily tadalafil for BPH and/or ED: Don't exceed 2.5 mg once daily Tadalafil for PAH: Avoid concomitant use
Angiotensin II receptor antagonists Potential additive hypotensive effects
Antiretroviral agents, HIV protease inhibitors (e.g., atazanavir, darunavir, fosamprenavir, lopinavir/ritonavir, ritonavir, saquinavir, tipranavir) Increased tadalafil AUC and increased risk of tadalafil-associated uncomfortable side effects (e.g., hypotension, visual changes, prolonged erection) Ritonavir: Increased systemic exposure of tadalafil by greater than twofold after first concurrent dose; however, no alteration of tadalafil exposure at steady-state ritonavir concentrations As-needed tadalafil for ED: Initial dose of 5 mg recommended; will not exceed 10 mg every 72 hours Once-daily tadalafil for BPH and/or ED: Maximum dose of 2.5 mg recommended Tadalafil for PAH: Inside of a patient already getting a PI for >a week, initiate tadalafil in a dosage of 20 mg once daily; may increase to 40 mg once daily based on patient response and tolerance If your PI is initiated inside of a patient already receiving tadalafil, discontinue tadalafil for >1 day before beginning the PI; after >1 week of therapy, may resume tadalafil in a dosage of 20 mg once daily, and increase as required to 40 mg once daily
Aspirin No boost in bleeding time reported
Bendroflumethiazide Possible additive hypotensive effects
Bosentan Decreased systemic exposure and peak plasma concentrations of tadalafil; no clinically important effects on bosentan pharmacokinetics No dosage adjustments recommended
Digoxin Clinically important pharmacokinetic interaction not observed
Enalapril Possible additive hypotensive effects
Erythromycin Potential increased AUC of tadalafil
Etravirine Possible decreased tadalafil concentrations Must increase tadalafil dosage based on clinical effect
Grapefruit juice Potential increased AUC of tadalafil
Hormonal contraceptives, oral Increased systemic exposure and peak plasma concentrations of ethinyl estradiol, but no substantial influence on levonorgestrel pharmacokinetics
Lovastatin Systemic exposure of lovastatin not substantially affected
Metoprolol Possible additive hypotensive effects
Midazolam Systemic exposure of midazolam not substantially affected
Nitrates and nitrites (e.g., nitroglycerin, isosorbide dinitrate, amyl nitrite) Potentiation of hypotensive effect Concomitant use is contraindicated (see Cautions) If nitrate administration necessary for a life-threatening condition, allow >two days to elapse between tadalafil administration and nitrate use; administer under close supervision with caution and appropriate hemodynamic monitoring
Nizatidine Clinically important effects on tadalafil pharmacokinetics not observed
Rifampin Possible decreased systemic exposure and peak plasma concentrations of tadalafil Tadalafil for ED and/or BPH: No dosage adjustments recommended Tadalafil for PAH: Avoid easy use in patients receiving long-term rifampin therapy
Theophylline Pharmacokinetic interaction unlikely Slight improvement in pulse (3 bpm) with concomitant therapy
Warfarin Clinically important effects on tadalafil pharmacokinetics not observed


        From National Library of Medicine 8600 Rockville Pike, Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health
        Page generic-online-pharmacy