Cialis Daily or As Needed: Choosing Between the Two Licensed Routes

Tadalafil is one drug with two separate licensed regimens attached to it, and almost every question people ask about dosing turns out to be a question about which of the two they are on.

NICE records that although PDE5 inhibitors were introduced as on-demand treatment, tadalafil "has also been approved for continuous, everyday use at 2.5 mg and 5 mg doses". That approval came later, and it was granted for two specific low strengths. The higher strengths kept the original licence: taken when needed, at a maximum of one dose in any 24 hours.

So the choice in front of you is not really a choice of tablet size. It is a choice between a medicine that is always present and a medicine that is taken on the occasions it is wanted. The strengths differ because the patterns differ, not the other way round.

At EveryDayMeds the daily route is supplied at 2.5mg and 5mg, and the as-needed route at 10mg and 15mg. This page sets out what separates the two, what the published evidence covers, and what to raise at consultation so that the decision is made on the right grounds.

Key points

• Continuous everyday use of tadalafil is approved at 2.5mg and 5mg
• The higher strengths are taken only when needed, at a maximum of one dose in any 24 hours
• Daily dosing reaches a steady level in the body within 5 days. The site describes this as 3 to 5 days for full effect
• An as-needed dose works from about 30 minutes, peaks near 2 hours, and efficacy is maintained for up to 36 hours
• The mean half-life of tadalafil is 17.5 hours in people who are healthy
• Daily tadalafil should not be combined with an additional as-needed tadalafil dose unless specifically directed by a prescriber
• The 5mg tablet holds a further licence, granted in October 2012, for the signs and symptoms of benign prostatic hyperplasia
• Both routes are prescription only and follow an online consultation with UK registered prescribers

The Two Licensed Ways of Taking Tadalafil

The same molecule, assessed twice, for two different jobs.

Continuous Everyday Use

A low strength taken once a day at roughly the same time, so that the medicine is present in the body all the time rather than being introduced for an occasion. The approved strengths for this are 2.5mg and 5mg.

Because the drug accumulates, the regimen has a warm-up period. Steady state, the point at which the amount in the body stops rising and settles at a consistent level, is reached within 5 days of once-daily dosing. Judging this route on its first day or two is judging it before it has arrived.

Use When Needed

A higher strength taken before anticipated activity, with a maximum of one dose in any 24 hours. There is no warm-up, because each dose is doing the whole job on its own.

An individual dose is effective from about 30 minutes, peaks at around 2 hours, and efficacy is maintained for up to 36 hours. That long window is often described as an advantage, and it is, but it is a window rather than a constant state. Sexual stimulation is still required throughout it.

Why the Daily Strength Is So Much Smaller

This is the part that misleads people, and it is worth spelling out properly.

Starting from nothing, a dose has to be large enough to produce an effect on its own. Once a steady level is already established, a much smaller tablet is enough to maintain it. The daily strength is not a weakened version of the as-needed strength. It is the dose required to hold a level that is already there.

Which means the arithmetic people do in their heads, comparing one tablet against another as if the numbers were directly proportional, does not describe what either regimen actually delivers.

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Cialis Daily or As Needed: How to Choose

Both routes are licensed and neither is a compromise. The deciding factors are practical rather than clinical in most cases, which is precisely why the decision belongs in a consultation rather than in a shopping basket.

What Points Towards Each Route

The table is not designed to produce a winner. Read down both columns and one of them will sound more like your life than the other, and that is the useful signal to bring to a prescriber.

What Should Not Decide It

The assumption that a larger number on the tablet means a stronger or better medicine. On the daily route the smaller tablet is doing a different job, not a lesser one.

Cost per tablet is also a poor guide, because the two routes use tablets at completely different rates. What matters is the cost of a month of treatment on the regimen you have actually been prescribed, not the price of one tablet against another.

And convenience should not outrank the clinical picture. Your other medicines, your blood pressure and your cardiovascular history all bear on which route is appropriate, and a prescriber weighs those alongside your preference rather than after it.

Maximum Dose: Why "One a Day" Means Two Different Things

Both routes cap at one dose in 24 hours, which is exactly why they get confused.

On the daily route, one a day is what you do. On the as-needed route, one a day is what you must not exceed. Same number, opposite meaning, and reading it the wrong way round is the single most common dosing error with this medicine.

Two doses in a day is outside the licence on either route. Never take an extra tablet because the first appeared not to work, and never double up after a missed dose. A dose that seems slow has usually not finished working rather than failed, given how long tadalafil remains active.

Never Run Both Routes at Once

Taking a daily tablet and adding an as-needed dose on top exceeds the maximum for either route. It is the most common thing that goes wrong when someone manages a change between regimens themselves, and it is the reason a switch is a prescriber decision rather than a purchasing one.

Alternate-Day Dosing Is Not a Middle Path

People sometimes try to invent a halfway option by taking a higher strength every other day. That is not one of the licensed regimens, and the pharmacology explains why it does not achieve what it appears to.

With a mean half-life of 17.5 hours, a dose taken 48 hours after the last one lands while a measurable amount of the previous dose is still present. So it is neither clean occasional use nor the accumulation pattern the daily route was studied at. It sits between two things that were each assessed, in a place that was not.

The licensed middle path already exists, and it is the daily strength.

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What the Daily Route Offers, and What It Does Not

Worth being accurate about which claims the evidence actually supports.

What it offers. Once steady state is reached, the medicine is present continuously rather than being introduced per occasion, so timing stops being a decision. It suits people who already have a daily medicine routine. And the 5mg tablet carries a separate licence, granted in October 2012, for the signs and symptoms of benign prostatic hyperplasia, so where a prescriber judges it appropriate one medicine may address both.

What it does not offer. It is not a way of getting more medicine into you, and it is not automatically the more effective route. It is a lower strength arriving at a steady level rather than a peak.

It also depends entirely on being taken. A missed day matters more on a regimen built around accumulation than it does on one built around single occasions, so a daily tablet that is only taken most days is not delivering the regimen that was prescribed.

Switching Between the Two Routes

Moving from one licensed regimen to the other is a prescriber decision, not something arranged by ordering a different pack.

What the Process Involves

1. You complete an online consultation covering your medical history, current medicines, blood pressure and heart health, and how the present regimen has been working
2. A UK registered prescriber reviews it and decides whether the other route is appropriate, and at which strength
3. If approved, the pharmacy dispenses it
4. You take it exactly as directed, at the same time each day if you have moved to the daily route
5. If it is not working as expected after a fair period, you go back to your prescriber rather than adjusting it yourself

On the daily route, the medicine reaches steady state within about 5 days, but your prescriber may recommend a longer period before assessing whether the treatment is working adequately.

What Not to Do When Changing

Do not overlap the two regimens, for the reason set out above.

Do not keep the old strength as a backup. If the new route is not suiting you, that is a conversation with your prescriber, and a leftover pack in the drawer quietly turns it into a decision you have already made on your own.

Do not change anything without declaring every medicine you take. Nitrates, nitric oxide donors and riociguat are absolute bars at every strength and on both routes. Alpha blockers prescribed for the prostate, such as alfuzosin, doxazosin and tamsulosin, need assessment because they and tadalafil both lower blood pressure.

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Side Effects and What the Trials Reported

The adverse effect profile belongs to tadalafil rather than to a particular strength or route.

Commonly reported effects across this class include headache, facial flushing, indigestion, and nasal and sinus congestion. Back pain, muscle aches and dizziness are also reported. Most are mild to moderate and often improve as the body becomes accustomed to treatment.

Figures From a 12-Week Trial of the Daily Route

These come from a 12-week trial of tadalafil 5mg daily in 212 men with lower urinary tract symptoms. They describe that strength, that duration and that group, and they are quoted here because this page is about the daily route.

In that trial 30.7%, 65 of 212, reported one or more treatment-emergent adverse event, 5.7% discontinued because of one, and 0.5%, a single participant, reported a serious adverse event.

Long Term Daily Use: What the Evidence Covers

The longest published follow-up on daily tadalafil that NICE records runs to one year.

A 1-year extension study in 427 men taking 5mg daily found 57.6% reported one or more treatment-emergent adverse events, most classed as mild at 44% or moderate at 45%. Serious adverse events were reported in 4.7%, and two cases were considered possibly related to treatment: one worsening of coronary heart disease and one episode of global amnesia.

Two honest observations about those numbers. The proportion reporting some adverse event rose over a year compared with 12 weeks, which is what a longer observation window produces rather than evidence of the medicine becoming less tolerable. And the discontinuation rate barely moved, 5.2% over a year against 5.7% over 12 weeks, which suggests most of what was reported was not severe enough to stop treatment.

What that evidence does not cover is several years of continuous use, because the study did not run that long. Anyone quoting a confident figure for five or ten years of daily tadalafil is going beyond what has been published, which is why long term use is reviewed periodically rather than settled once.

Does Tadalafil Stop Working Over Time?

There is no established recommendation to routinely increase tadalafil because of tolerance. If treatment appears less effective over time, other factors should also be considered, including changes in cardiovascular health, other medicines, alcohol use, stress and the underlying cause of erectile dysfunction. A prescriber should review persistent changes in response before any dose adjustment.

• The underlying condition can progress, which changes what the medicine is being asked to do
• Blood pressure, blood sugar and cardiovascular health all affect response, and all change over time
• Medicines started since treatment began can interact
• Alcohol, tiredness and stress affect a given occasion without affecting the drug
• Expectation shifts, and treatment that once felt remarkable can feel ordinary while doing exactly the same thing

Increasing what you take is not the answer to any of those. Treatment that has stopped working as it did is a reason for review, because the reason usually lies outside the tablet.

What Weight to Give Online Discussion Threads

A good deal of what circulates about dosing comes from anonymous forums, and it is worth being direct about what that is worth.

Posted accounts are not a study. They carry no denominator, no verification, no record of what else the person was taking and no follow-up. Someone reporting that an unlicensed pattern suited them tells you nothing about whether it is safe, and neither does someone reporting the opposite.

The useful part of those threads is the questions asked in them, which is why several are answered on this page. The dosing advice is not useful, and following it means using a prescription only medicine outside the pattern the regulator assessed.

Getting Assessed and What to Raise at Consultation

Both routes are prescription only, so the process is identical whichever you are considering. An online consultation with UK registered prescribers at EveryDayMeds covers daily tadalafil at 2.5mg and 5mg and as-needed tadalafil at the higher strengths, alongside branded Cialis tablets.

Raise these specifically, because they change the answer:

• Every medicine you take, including anything bought without a prescription, and nitrates above all
• Any heart condition, previous stroke, angina or heart failure
• Your blood pressure, and whether you take anything for it
• Any prostate symptoms or prostate medication
• How often treatment is genuinely needed, answered honestly, because that is what decides between the two routes
• What has and has not worked so far

A prescriber can only assess what you tell them, and an incomplete answer about nitrates or a heart condition is the one thing on this page that can genuinely cause harm.

EveryDayMeds is a GPhC registered pharmacy, registration number 9012878, operating as OVIO LTD. Treatment is supplied only after clinical assessment, and all medication is genuine and UK sourced.

When to Seek Urgent Help

• An erection lasting more than 4 hours needs immediate medical attention
• Sudden loss of vision in one or both eyes, or sudden loss or reduction of hearing, means stopping treatment and being seen urgently
• Chest pain during or after use is an emergency, and you must tell whoever treats you that you have taken tadalafil, because nitrates must not be given
• Fainting or collapse needs assessment

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