Cialis

Ci·al·is (s-ls)

A trademark for the drug tadalafil.

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Cialis,

a trademark for tadalafil.

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tadalafil

Cialis

Pharmacologic class: Phosphodiesterase type 5 (PDE5) inhibitor

Therapeutic class: Anti-erectile dysfunction agent

Pregnancy risk category B

Action

Inhibits PDE5, increasing cyclic guanosine monophosphate level and enhancing erectile function

Availability

Tablets: 5 mg, 10 mg, 20 mg

⊘Indications and dosages

➣ Erectile dysfunction

Adults: Initially, 10 mg P.O. before anticipated sexual activity; may increase to 20 mg or decrease to 5 mg based on patient response and tolerance. For most patients, maximum recommended dosing frequency is once daily.

Dosage adjustment

• Mild to moderate hepatic impairment or renal insufficiency

Contraindications

• Hypersensitivity to drug or its components
• Concurrent use of organic nitrates (regularly or intermittently)
• Concurrent use of alpha-adrenergic agonists (except tamsulosin 0.4 mg/day)

Precautions

Use cautiously in:
• cardiac risk that makes sexual activity inadvisable, renal insufficiency, hepatic impairment, left ventricular outflow obstruction, erectile dysfunction whose cause hasn't been evaluated, conditions that increase risk of priapism
• concurrent use of potent CYP450-3A4 inhibitors.

Administration

• Know that patient should take drug (with or without food) before anticipated sexual activity.

Route	Onset	Peak	Duration
P.O.	Rapid	30 min-6 hr	Up to 36 hr

Adverse reactions

CNS: headache, fatigue, dizziness, insomnia, hyperesthesia, paresthesia, drowsiness, vertigo, asthenia

CV: angina pectoris, chest pain, hypertension, hypotension, orthostatic hypotension, palpitations, syncope, tachycardia, myocardial infarction

EENT: blurred vision, color vision changes, conjunctivitis, eye pain, increased lacrimation, eyelid swelling, epistaxis, nasal congestion, pharyngitis

GI: nausea, vomiting, diarrhea, dyspepsia, esophagitis, gastroesophageal reflux, gastritis, upper abdominal pain, dysphagia, dry mouth

GU: increased or spontaneous erection

Musculoskeletal: myalgia; back, neck, limb, and joint pain

Respiratory: dyspnea

Skin: pruritus, rash, sweating

Other: facial edema, pain

Interactions

Drug-drug. Alpha-adrenergic blockers (except tamsulosin 0.4 mg/day): marked blood pressure decrease

Angiotensin receptor blockers, enalapril, metoprolol: decreased blood pressure

CYP450-3A4 inducers (such as carbamazepine, phenobarbital, phenytoin, rifampin): decreased tadalafil blood level

CYP450-3A4 inhibitors (such as erythromycin, itraconazole, ketoconazole, ritonavir): increased tadalafil blood level

Theophylline: slight increase in heart rate

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, uric acid: increased levels

Drug-food. Grapefruit juice: increased drug blood level

Patient monitoring

• Monitor for drug efficacy.

Patient teaching

• Advise patient to take before anticipated sexual activity.
☞ Caution patient never to take concurrently with nitrates.
☞ Instruct patient to stop sexual activity and contact prescriber immediately if chest pain, dizziness, or nausea occurs.
• Instruct patient to contact prescriber if erection lasts more than 4 hours.
• Tell patient drug can cause serious interactions with many common drugs. Instruct him to tell all prescribers he's taking it.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Inform patient that drug may cause temporary blood pressure drop, leading to light-headedness if he stands up suddenly. Advise him to rise slowly and carefully.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.