How is Cialis (tadalafil) typically ordered by a healthcare provider?

How Cialis (Tadalafil) is Typically Ordered

Cialis is ordered in one of two distinct regimens: as-needed dosing (10-20 mg taken 30 minutes to 36 hours before sexual activity, maximum once daily) or daily dosing (2.5-5 mg taken at the same time each day regardless of sexual activity timing). 1

Dosing Regimens

As-Needed (PRN) Dosing

• Starting dose is typically 10 mg, taken at least 30 minutes before anticipated sexual activity 1
• The medication provides a window of effectiveness lasting up to 36 hours after dosing 1
• Maximum frequency is once per 24 hours 1
• Dose can be increased to 20 mg or decreased to 5 mg based on efficacy and tolerability 1
• Sexual stimulation is required for the medication to work 1

Daily Dosing

• Starting dose is 2.5-5 mg taken once daily at approximately the same time each day 1
• This regimen eliminates the need to time medication with sexual activity, allowing for spontaneous intimacy 2
• Sexual activity can be attempted at any time between doses 1
• Maximum dose is 5 mg once daily 1
• Daily dosing is FDA-approved for treating both erectile dysfunction and benign prostatic hyperplasia (BPH) symptoms simultaneously when using the 5 mg dose 2

Critical Pre-Prescribing Requirements

Absolute Contraindications to Screen For

• Any form of nitrate use (oral, sublingual, transdermal, or inhaled) is an absolute contraindication due to risk of fatal hypotension 2, 1
• Concurrent use of guanylate cyclase stimulators like riociguat 1
• Patients already taking other PDE5 inhibitors or ADCIRCA (tadalafil for pulmonary hypertension) 1

Cardiovascular Risk Assessment

• Assess whether the patient can perform moderate physical activity (equivalent to climbing two flights of stairs) 2
• Low-risk patients who can perform moderate activity can safely receive tadalafil without cardiology consultation 2
• Refer to cardiology before prescribing if the patient cannot perform moderate exercise or has indeterminate cardiovascular risk 2
• Low-risk patients include those with asymptomatic coronary artery disease with <3 risk factors, controlled hypertension, mild stable angina, successful coronary revascularization, uncomplicated past MI, mild valvular disease, and CHF NYHA class I 2

Drug Interaction Screening

• Alpha-blockers can cause dangerous blood pressure drops when combined with tadalafil 1
• HIV protease inhibitors (ritonavir), antifungals (ketoconazole, itraconazole), and certain antibiotics (clarithromycin, erythromycin) require dose adjustments 1
• Severe hepatic impairment generally contraindicates PDE5 inhibitor use 2

Dose Selection Strategy

Choosing Between As-Needed vs. Daily Dosing

• For couples preferring spontaneous rather than scheduled sexual activity, daily dosing (2.5-5 mg) is the preferred regimen 2
• For patients with both ED and BPH symptoms, prescribe tadalafil 5 mg once daily as it treats both conditions simultaneously 2
• As-needed dosing is appropriate for patients with infrequent sexual activity or those who prefer to time medication with planned intimacy 1

Dose Titration Principles

• Unlike sildenafil and vardenafil, tadalafil does NOT show dose-dependent improvement between 5 mg, 10 mg, and 20 mg doses 3, 2, 4
• The choice between 10 mg and 20 mg for as-needed dosing should be based primarily on tolerability rather than expecting dramatically better efficacy at higher doses 2
• Titrate doses up or down to find the optimal balance between efficacy and side effects 2

Defining an Adequate Trial

An adequate trial consists of at least 5 separate attempts at the maximum dose before declaring treatment failure 2

Common reasons for apparent treatment failure include:

• Inadequate number of attempts (fewer than 5) 2
• Improper timing of the dose 2
• Lack of sexual stimulation (which is required for the medication to work) 2, 1
• Unaddressed hormonal abnormalities, particularly testosterone deficiency 2
• Food or drug interactions 2
• Heavy alcohol use (more than 5 drinks) 1

Special Populations

Patients with Diabetes or Post-Prostatectomy

• These patients have more severe ED at baseline and may respond less robustly to PDE5 inhibitors 2
• However, tadalafil remains effective in these populations 3

Patients with Testosterone Deficiency

• For men with both ED and testosterone deficiency, combining tadalafil with testosterone therapy is more effective than tadalafil alone 2
• Testosterone therapy alone is not effective monotherapy for ED 2

Patients Previously on Other PDE5 Inhibitors

• Switching to daily tadalafil can restore normal erectile function (IIEF-EF ≥26) in men who had incomplete response to maximum-dose as-needed PDE5 inhibitors 5
• In one study, 39-40% of men achieved normal erectile function with daily tadalafil after failing to achieve this with maximum-dose as-needed therapy 5

Patient Counseling Points

Critical Information to Prevent Treatment Failure

• Sexual stimulation is necessary for tadalafil to work 2, 1
• More than one trial may be required to establish efficacy 2
• For as-needed dosing, the medication can be effective from 30 minutes up to 36 hours after taking it 1
• Avoid excessive alcohol consumption (more than 5 drinks) as this increases risk of headache, dizziness, and hypotension 1

Common Side Effects

• Most common adverse effects are headache, dyspepsia, back pain, flushing, nasal congestion, and myalgia 2, 1
• Back pain and muscle aches typically occur 12-24 hours after dosing and resolve within 2 days 1
• Most adverse events are transient and mild to moderate in severity 4

Emergency Nitrate Protocol

• If emergency nitrate administration is required, wait at least 48 hours after the last tadalafil dose before giving nitrates 2
• This must be done under close medical supervision with continuous patient monitoring 2

Follow-Up Management

• Schedule follow-up within 4-12 weeks after initiating therapy to assess efficacy and tolerability 6
• Verify that cardiovascular health hasn't changed 2
• Review any new medications for potential interactions 2
• Assess treatment effectiveness and side effects 2
• Before switching therapies, evaluate whether the trial was adequate by addressing hormonal abnormalities, drug interactions, timing/frequency of dosing, adequacy of sexual stimulation, alcohol use, and relationship issues 2