Cialis Dosage: How to Take Cialis Safely and Effectively

Cialis is the original brand name for tadalafil, manufactured by Eli Lilly.

Since the Cialis patent expired, generic tadalafil has become widely available and is now the most commonly dispensed version in the UK.

Key points:

• Cialis and generic tadalafil contain the same active ingredient in the same doses
• Generic tadalafil must meet the same regulatory standards (bioequivalence, purity, stability) as the branded product
• The main difference is price: generic tadalafil is significantly cheaper
• Your pharmacist may dispense generic tadalafil even if the prescription says "Cialis", unless the prescriber has specifically stated otherwise

For dosing purposes, all guidance that applies to Cialis applies equally to generic tadalafil. In this article, we use the names interchangeably.

If you are currently taking generic tadalafil, the same dosing information applies.

As-needed dosing is the most commonly prescribed approach for men who do not require treatment every day.

Starting dose: 10 mg

• Take one 10 mg tablet at least 30 minutes before sexual activity
• The medicine can take up to 2 hours to reach peak levels, but many men notice effects within 30 to 60 minutes
• Cialis lasts significantly longer than sildenafil: effects can persist for up to 36 hours
• Do not take more than one dose in 24 hours

Increasing to 20 mg:

• If 10 mg does not produce a satisfactory result after several attempts, your prescriber may increase the dose to 20 mg
• 20 mg is the maximum single dose and should not be exceeded

Practical tips:

• Cialis can be taken with or without food; fat does not significantly affect absorption
• Moderate alcohol is acceptable, but heavy drinking can impair both erectile function and the medicine's effectiveness
• Because of its long duration, some men prefer to take Cialis on a Friday evening to cover the entire weekend

Sexual stimulation is still required for the medicine to work. Cialis does not produce an automatic erection.

Daily Cialis is designed for men who prefer not to plan around a tablet or who are sexually active three or more times per week.

How it works:

• Take one low-dose tablet every day at the same time
• After approximately 5 days of daily dosing, tadalafil reaches a steady level in the bloodstream
• You can then have sexual activity at any time without needing to take an extra tablet

Starting dose: 2.5 mg daily

• If the response is inadequate after 4 to 8 weeks, the dose can be increased to 5 mg daily
• 5 mg is also the dose used for benign prostatic hyperplasia (BPH)

Who benefits most from daily Cialis:

• Men in regular sexual relationships who value spontaneity
• Men with co-existing BPH and lower urinary tract symptoms
• Men who experience more side effects with the higher as-needed doses (daily low-dose therapy produces a steadier drug level with fewer peaks)

Daily Cialis is not appropriate for everyone. If you have severe renal impairment, your prescriber may advise against daily dosing. Periodic review is recommended to confirm ongoing need.

Dose changes should always be made in consultation with your prescriber.

Reasons to consider a dose increase:

• 10 mg as-needed has been tried on multiple occasions without adequate effect
• Side effects at 10 mg were mild and tolerable
• No contraindications to the higher dose exist

Reasons to consider a dose decrease:

• Bothersome side effects such as headache, back pain or nasal congestion at the current dose
• Addition of an interacting medicine (e.g. a CYP3A4 inhibitor such as erythromycin or ketoconazole)
• Development of hepatic or renal impairment

BNF guidance on dose limits with interacting medicines:

• With potent CYP3A4 inhibitors: maximum as-needed dose is 10 mg, not more than once every 72 hours
• For daily dosing with potent CYP3A4 inhibitors: maximum 2.5 mg daily

Important: do not attempt to adjust your dose by splitting or combining tablets without guidance. While some tablets can be split, this is not appropriate for all formulations.

Speak with your pharmacist if cost is a concern.

Cialis carries the same safety warnings as all PDE5 inhibitors.

Absolute contraindications:

• Concurrent use of nitrate medicines (GTN spray, isosorbide mononitrate or dinitrate, amyl nitrite). The combination can cause life-threatening hypotension.
• Known hypersensitivity to tadalafil or any excipient
• Recent stroke or myocardial infarction (within the last 90 days)
• Unstable angina or angina triggered during sexual intercourse
• Severe uncontrolled hypertension or hypotension (systolic below 90 mmHg)
• Recent history of NAION (non-arteritic anterior ischaemic optic neuropathy)

Common side effects:

• Headache, flushing, nasal congestion, dyspepsia
• Back pain and myalgia are more common with tadalafil than with sildenafil, typically occurring 12 to 24 hours after dosing and resolving within 48 hours

When to seek urgent medical help:

• Erection lasting more than 4 hours (priapism)
• Sudden loss of vision in one or both eyes
• Sudden decrease or loss of hearing
• Chest pain during or after sexual activity

Always report side effects via the Yellow Card Scheme or to your prescriber.