TL;DR
- Prothiaden is the brand name for amitriptyline, a tricyclic antidepressant.
- It's prescribed for depression, chronic pain, and migraine prevention.
- Typical starting dose is 25mg at night, gradually increased to 50‑150mg as tolerated.
- Common side effects: dry mouth, drowsiness, constipation, weight gain.
- Never mix with MAO inhibitors or alcohol; discuss all other meds with your GP.
What is Prothiaden?
Prothiaden is the Australian trade name for amitriptyline, a tricyclic antidepressant (TCA) discovered in the 1960s. It works by boosting the brain’s serotonin and norepinephrine levels, which helps lift mood and modulate pain signals. While originally developed for major depressive disorder, clinicians now use it off‑label for conditions like fibromyalgia, tension‑type headache, and neuropathic pain.
In the Australian Pharmaceutical Benefits Scheme (PBS), Prothiaden is listed for depression when other first‑line treatments have failed. The drug is taken orally, usually as a film‑coated tablet, and it’s available in 25mg, 50mg, and 100mg strengths.
How to Take Prothiaden (Dosage & Administration)
Getting the dose right is crucial because TCAs have a narrow therapeutic window. Below is a step‑by‑step guide that works for most adults, but always follow your prescriber’s exact instructions.
- Start Low: Begin with 25mg taken at bedtime. This minimizes daytime drowsiness.
- After 3-7 days, if you tolerate the initial dose, increase by 25mg.
- Typical maintenance ranges between 50mg and 150mg nightly. Some chronic‑pain protocols may go up to 200mg, but only under specialist supervision.
- Take the tablet with a full glass of water. If you experience stomach upset, a light snack can help.
- Do not abruptly stop. Taper down by 25mg every 1-2 weeks to avoid withdrawal symptoms such as nausea, headache, and flu‑like feelings.
Special populations:
- Elderly: Start at 10-25mg and increase slowly; they’re more prone to anticholinergic side effects.
- Pregnancy & Breastfeeding: Use only if benefits outweigh risks; amitriptyline passes into breast milk.
- Kidney or Liver Impairment: Dose adjustments may be needed; your doctor will run liver function tests.
| Strength | Typical Starting Dose | Maximum Recommended Dose |
|---|---|---|
| 25mg | 25mg nightly | 100mg daily |
| 50mg | 50mg nightly (after titration) | 150mg daily |
| 100mg | Not used as starter | 200mg daily (specialist only) |
Side Effects
Amitriptyline’s anticholinergic properties cause a predictable side‑effect profile. Most are mild and fade after a few weeks, but some require medical attention.
- Very Common (≥10%): Drowsiness, dry mouth, constipation, blurred vision, weight gain.
- Common (1‑10%): Increased heart rate, orthostatic hypotension, urinary retention, sweating, tremor.
- Rare (<1%): Seizures, cardiac arrhythmias, severe allergic reactions, suicidal thoughts (especially early in treatment).
Tips to manage everyday side effects:
- Stay hydrated and chew sugar‑free gum to combat dry mouth.
- Take the medication at bedtime to use drowsiness as a sleep aid.
- Increase dietary fibre and water to ease constipation.
- Report any sudden heart palpitations, fainting, or mood changes to your GP immediately.
Precautions & Interactions (including FAQs)
Prothiaden interacts with a surprisingly long list of drugs, many of which are common in everyday life. Below is a quick‑reference table of the most critical interactions.
| Drug/Class | Interaction Effect | Management |
|---|---|---|
| MAO inhibitors (e.g., phenelzine) | Serotonin syndrome - potentially fatal | Stop MAOi 14days before starting amitriptyline. |
| SSRIs / SNRIs | Increased risk of serotonin syndrome | Avoid concurrent use unless closely monitored. |
| Anticholinergics (e.g., diphenhydramine) | Exacerbated dry mouth, constipation, blurred vision | Use lowest effective dose or alternative. |
| Warfarin | Potential increase in INR | Monitor INR more frequently. |
| Alcohol | Enhanced sedation, respiratory depression | Limit or avoid alcohol. |
Frequently asked questions
- Can I drive while on Prothiaden? Avoid driving or operating heavy machinery until you know how the drug affects you, usually after 1-2 weeks.
- How long does it take to feel better? Antidepressant effects may appear after 2-4 weeks; pain relief often begins sooner, within a few days.
- What if I miss a dose? Take it as soon as you remember if it’s still daytime; if bedtime is near, skip it and resume your regular schedule.
- Is Prothiaden addictive? It’s not considered addictive, but stopping abruptly can cause withdrawal symptoms.
- Can I take it with over‑the‑counter sleep aids? Most OTC antihistamines (e.g., diphenhydramine) add to sedation and should be avoided without doctor approval.
Next Steps & Troubleshooting
If you’re starting Prothiaden, keep a simple log:
- Record the dose, time taken, and any side effects each day.
- Note mood or pain level on a 1‑10 scale.
- Bring the log to your next appointment - it helps your doctor fine‑tune the dosage.
When problems arise:
- Excessive Drowsiness: Try taking the tablet earlier (e.g., 10pm) or discuss a dose reduction.
- Severe Constipation: Increase fibre, consider a gentle stool softener, and talk to your GP if it persists.
- Cardiac Symptoms: Stop the medication and seek urgent care; you may need an ECG before restarting.
Finally, never share your medication with anyone else, and always keep Prothiaden out of reach of children. With careful monitoring, the drug can be a valuable tool for managing depression and chronic pain.