Cialis (Tadalafil)
Complete patient guide for uses, dosage, side effects, and safety information
Prescription RequiredQuick Facts
What Is Cialis Used For?
Cialis contains tadalafil and belongs to a group of medicines called phosphodiesterase type 5 inhibitors. It’s prescribed to help men with specific sexual and urinary health issues.
Primary Uses
Cialis treats erectile dysfunction (impotence) in men – when you cannot get or maintain an erection suitable for sexual activity. It also treats urinary symptoms from benign prostatic hyperplasia, a common condition where the prostate gland enlarges with age, causing difficulty starting urination, feeling like the bladder doesn’t empty completely, and needing to urinate more frequently, even at night.
How It Works
For erectile dysfunction, Cialis works after sexual stimulation by helping blood vessels in the penis relax, allowing blood flow that improves erectile function. You and your partner still need foreplay – Cialis only works when you’re sexually aroused. For prostate symptoms, Cialis improves blood flow to and relaxes muscles of the prostate and bladder, which may reduce urinary symptoms.
Good to know: Cialis only treats erectile dysfunction when you are sexually aroused – it’s not an automatic response and requires natural sexual stimulation.
How to Take Cialis
Always take Cialis exactly as your doctor prescribed. You should not take Cialis more than once a day. Swallow one tablet whole with a full glass of water.
Dosage Instructions
For erectile dysfunction, Cialis can be taken two ways: On-demand dosing (10mg or 20mg) taken 30-60 minutes before anticipated sexual activity – not for daily use. Once-daily dosing (5mg) for men who anticipate frequent use (at least twice weekly) – allows erection when sexually stimulated anytime during 24 hours. For urinary symptoms from enlarged prostate: 5mg taken once daily. Kidney disease patients: 10mg maximum for on-demand use; once-daily not recommended for severe kidney problems. Liver disease patients: 10mg recommended; follow doctor’s advice for severe liver problems. No special dosing needed for elderly or diabetic patients.
Important: Never take once-daily dosing and on-demand dosing at the same time. Cialis can be effective for up to 36 hours for on-demand dosing.
Available Tablet Strengths
Side Effects
Like all medications, this medicine can cause side effects. Most are mild and temporary, but some require medical attention.
Common Side Effects
These side effects occur relatively frequently and usually don’t require emergency care:
- headache or migraine
- dizziness
- flushing
- sweating
- nausea or vomiting
- indigestion
- stomach pain
- diarrhea
- heartburn
- back pain
- muscle pain
- tiredness (fatigue)
- bleeding nose
- sore throat
- nasal congestion
- red eyes, eye pain, swelling of eyelids
- temporary blurred vision
- changes in color vision
- skin rash, swelling of face and hives
Seek immediate medical attention if you experience:
- chest pain
- increased heart beat
- prolonged and painful erection
- erection lasting longer than 4 hours
- sudden decrease or loss of hearing
- seizures
- central serous chorioretinopathy (vision problems including distorted, dimmed or blurred vision, dark areas in central vision, bent lines, objects appearing smaller or further away, color changes)
- non-arteritic anterior ischemic optic neuropathy (NAION) causing sudden vision loss in one or both eyes
Important Warnings
Certain medical conditions and medications make Cialis unsafe. Always tell your doctor about all your health conditions and medications.
Who Should Not Take Cialis
Do not use Cialis if you: are allergic to tadalafil or any ingredients; currently take nitrates for chest pain or heart conditions; use recreational drugs like ‘poppers’ or amyl nitrite; take guanylate cyclase stimulators like riociguat; have heart/blood vessel problems making sexual activity inadvisable; have heart problems like angina, arrhythmias, or heart failure; had a heart attack in the last 3 months; had a stroke in the last 6 months; have unusually high/low or untreated blood pressure; have vision loss in one eye from NAION.
Medical Conditions to Discuss
Check with your doctor if you have: liver or kidney problems; heart problems or previous heart attack; blood vessel problems; sickle cell anemia; multiple myeloma; leukemia; penis deformation; sudden vision changes, loss, or distortion. If you experience vision problems while taking Cialis, stop immediately and contact your doctor.
Use in Women and Children
Cialis is not intended for use by women or children under 18 years.
Elderly Patients: Patients 75 years and over have higher chances of side effects like dizziness and diarrhea. Your doctor will assess if Cialis is suitable for you.
Drug Interactions
Some medicines may interfere with Cialis or affect how it works. Tell your doctor about all medicines, vitamins, and supplements you take.
Grapefruit interaction: Grapefruit juice may interact with Cialis – discuss with your doctor or pharmacist.
- nitrates (glyceryl trinitrate, isosorbide mononitrate, sodium nitroprusside)
- guanylate cyclase stimulators (riociguat)
- antibiotics (rifampicin, erythromycin, clarithromycin)
- seizure medicines (phenytoin, phenobarbitone, carbamazepine)
- antifungal medicines (ketoconazole, itraconazole)
- HIV protease inhibitors (ritonavir, saquinavir)
- blood pressure medicines (metoprolol, irbesartan, enalapril)
- alpha-blockers (prazosin, doxazosin)
- 5-alpha reductase inhibitors (finasteride)
- warfarin
- other PDE5 inhibitors (sildenafil)
- grapefruit juice
- large amounts of alcohol
Alcohol & Driving
Be careful with alcohol and driving while taking Cialis, as it may affect your abilities and response to the medication.
Alcohol
Cialis can be taken with or without alcohol, but drinking alcohol may affect your ability to get an erection, so avoid excessive drinking. When taking Cialis with large amounts of alcohol, some men may experience dizziness.
Driving and Operating Machinery
Be careful driving or operating machinery until you know how Cialis affects you, as it may cause dizziness or other side effects that could impair your abilities.
Storage
Store Cialis below 25°C in a cool, dry place away from moisture, heat, and sunlight. Keep tablets in the original pack until time to take them. Do not store in the bathroom, near a sink, in the car, or on window sills. Keep where young children cannot reach it.
Overdose Information
If you think you have taken too much Cialis, you may need urgent medical attention. Immediately phone the Australian Poisons Information Centre (13 11 26) or New Zealand National Poisons Centre (0800 POISON or 0800 764 766), contact your doctor, or go to the nearest hospital Emergency Department. Do this even if there are no signs of discomfort or poisoning.
Frequently Asked Questions
For on-demand dosing, Cialis should be taken 30-60 minutes before sexual activity. In some men, it can work as early as 16 minutes, but it’s recommended to allow 1 hour the first time. For once-daily dosing, it may take up to 1 week for full effect on erectile dysfunction.
Yes, Cialis can be taken with or without food. Food does not affect how well Cialis works.
Cialis has been proven effective for up to 36 hours for on-demand dosing. This means you can take Cialis and obtain an erection when sexually stimulated at any time during the 36 hours after taking it.
Cialis can be taken with alcohol, but drinking may affect your ability to get an erection, so avoid excessive drinking. Large amounts of alcohol combined with Cialis may cause dizziness in some men.
For once-daily dosing, take your missed dose as soon as you remember, but never take more than one dose per day. For on-demand dosing, only take when needed before sexual activity.
Patients 75 years and over have a higher chance of experiencing side effects like dizziness and diarrhea. Your doctor will assess if Cialis is suitable for you, but no special dosing consideration is needed for elderly patients.
Sometimes if you’re feeling anxious or nervous, you may not respond to the first tablet. Don’t give up – it may take a few doses before you get the full benefit of Cialis.
Important Disclaimer
This information is intended for general educational purposes only and should not be considered medical advice. Always consult your healthcare provider or pharmacist before starting, stopping, or changing any medication.
If you think you may have a medical emergency, call your doctor or emergency services immediately.