Tadalafil
Also known as: Cialis, Megalis, Tadacip
Important: This is informational content only. Always consult Dr. Ambrish Singal or your psychiatrist before starting, stopping, or changing any medication.
What is Tadalafil?
Tadalafil is a long-acting PDE5 inhibitor for erectile dysfunction. Its 36-hour duration of action (vs. 4-6 hours for sildenafil) allows more spontaneity and it can also be taken daily at a low dose.
How It Works
Same as sildenafil - inhibits PDE5, preserving cGMP and enhancing blood flow to the penis. Its longer half-life (17.5 hours) provides extended therapeutic effect.
Uses
How This Drug Starts Working
Effects typically begin within 1-4 weeks depending on the condition being treated. Full therapeutic effect usually takes 4-8 weeks.
Week-by-Week Timeline
Week 1: Medication reaching therapeutic blood levels. Some initial side effects may appear as body adjusts.
Week 2-3: Initial therapeutic effects beginning. Side effects often settling.
Week 4-6: Significant therapeutic benefit in most patients.
Week 8+: Full effect established. Treatment response can be properly assessed.
What Changes First?
Physical symptoms (sleep, appetite, energy) typically improve before emotional and cognitive symptoms. Others may notice improvement before you feel it yourself.
Why Does It Take Time?
Psychiatric medications work by gradually rebalancing brain chemistry and neural circuits. Unlike pain medications that block a sensation, these drugs help your brain rebuild healthy patterns — which requires time.
Complete Dosage Guide
How to Take
Take exactly as prescribed by your doctor. Maintain consistent timing each day.
Starting Dose
Your doctor will determine the appropriate starting dose based on your condition, age, weight, and other factors.
Dose Increases
Dose adjustments are made gradually based on your response and side effects. Follow your doctor's instructions for any changes.
Maximum Dose
Your doctor will not exceed safe maximum doses. Never take more than prescribed.
When to Take
Take at the same time daily for best results. Ask your doctor whether morning or evening is better for your specific medication.
If You Miss a Dose
If you miss a dose, take it as soon as you remember unless close to your next dose. Never double up. Contact your doctor if you miss multiple doses.
Food & Drink
Ask your doctor or pharmacist about specific food interactions for your medication.
How Long to Take
Duration of treatment varies by condition. Never stop medication without discussing with your doctor first — some medications require gradual tapering.
Dosage by Age Group
adult
As needed: 10mg before activity. May adjust to 5-20mg. Maximum one dose per 36 hours. Daily use: 2.5-5mg once daily.
child
Not applicable.
elderly
No specific adjustment but start conservatively.
Special Populations
Pregnancy
Not applicable for ED use.
Kidney Conditions
As needed: start 5mg if CrCl 30-50, max 10mg if CrCl <30. Daily: 2.5mg if CrCl <30.
Liver Conditions
Max 10mg as needed. Avoid daily dosing in severe hepatic impairment.
Side Effects
Common
- Headache
- Back pain
- Myalgia
- Nasal congestion
- Flushing
- Dyspepsia
- Limb pain
Serious
- Priapism
- Sudden vision or hearing loss
- Severe hypotension with nitrates (CONTRAINDICATED)
- Cardiac events
What You Should Know
Overdose Risks
Similar to sildenafil. Extended effects due to long half-life. Supportive care.
Safe Discontinuation
No withdrawal. Can be stopped anytime.