Rivastigmine
Drug class: Acetylcholinesterase Inhibitor
Rivastigmine (EXELON) (中文: 利凡斯的明) is a reversible acetylcholinesterase inhibitor. Rivastigmine is selective for the CNS and is used for the treatment of mild to moderate dementia associated with Parkinson’s disease.
Pronunciation
Rivastigmine 1.5mg (EXELON 1.5mg)
Rivastigmine 3mg (EXELON 3mg)
Rivastigmine 4.5mg (EXELON 4.5mg)
Common Strengths
- Oral Capsules: 1.5 mg, 3 mg, 4.5 mg, 6 mg
- Transdermal Patches: 4.6 mg/24 hours, 9.5 mg/24 hours, 13.3/24 hour
Drug Trade Names
- Exelon
Drug Usage
For managing symptoms of dementia, improving cognitive function and daily living activities in affected individuals. It is not a cure but may help slow the progression of symptoms.
Mechanism of Action
Rivastigmine works by inhibiting acetylcholinesterase, the enzyme responsible for breaking down acetylcholine in the brain. This inhibition leads to increased level of acetylcholine, which is crucial for memory and cognitive function.
Route of Administration
Rivastigmine can be administered:
- Orally (capsules)
- Transdermally (patch)
Dosage
- Initial: 1.5 mg orally twice daily; may increase every two weeks up to a maximum of 6 mg twice daily.
- Transdermal: Start with a patch delivering 4.6 mg/24 hours, with potential increases based on tolerance.
Conversion of oral rivastigmine to patches are as follows
- Those taking ≤6 mg daily of oral rivastigmine may be switched to 4.6 mg/24 hours patch.
- Those taking more than 6 mg daily may be switched to 9.5 mg/24 hours patch.
- The first patch should be applied on the day following the last oral dose.
How quickly dose Rivastigmine patch work?
Rivastigmine may take as long as 12 weeks to begin working and individual response to this medication will vary.
Side Effects
| Frequency | Adverse reactions |
|---|---|
| Common Side Effects | Nausea |
| Vomiting | |
| Loss of appetite | |
| Diarrhea | |
| Dizziness | |
| Serious Side Effects | Sever allergic reactions (e.g. difficulty greathing) |
| Seizures | |
| Involuntary movement or tremors |
Pharmacokinetics
It is available in two primary formulations: capsules and transdermal patches. The pharmacokinetics of these two forms differ significantly
- The transdermal patch provides a continuous release of rivastigmine over 24 hours, leading to a smoother pharmacokinetic profile with lower peak plasma concentrations compared to oral capsules.
- The patches are designed to minimize fluctuations in drug levels, which can enhance tolerability and compliance among patients.
Summary of Key Differences
| Feature | Capsules | Transdermal Patch |
|---|---|---|
| Absorptions Peak Time | ~1 hour | Continuous over 24 hours |
| Elimination half-life | ~1 hour | ~1 hour |
| Dosing Flexibility | Requires titration | Steady release |
Drug Management
Monitoring
- acetylcholinesterase inhibitor may increase gastric acid secretion, so patients should be monitored closely for GI bleeding, especially those receiving concurrent NSAID drugs.
- check body weight regularly
- monitor the cognitive, global functions, and ADL activities
- monitor the sleeping quality
Caution
- Cardiovascular conduction disorders such as sick-sinus syndrome
- Susceptibility to peptic ulcers
- Asthma, chronic obstructive pulmonary disease
- People who have a predisposition to seizures
- Concomitant antipsychotic treatment – increased risk of neuroleptic malignant syndrome
Contraindications
Patients with known hypersensitivity to rivastigmine.
Hepatic impairment
Titrate according to individual tolerability in mild to moderate impairment; use with caution in severe impairment.
Renal impairment
Titrate according to individual tolerability
Effects on ability to drive and use machinery
Rivastigmine can cause fatigue, dizziness and muscles, mainly when initiating or increasing the dose. The treating doctor should routinely evaluate the ability of patients on donepezil to continue driving or operating complex machines.
FAQ
How should I take Rivastigmine?
If you are taking the capsules, swallow them whole with a full glass of water, with your morning and evening meals. Do not open or crush the capsules.
If you are using the patch, apply it to a clean, dry and hairless skin area on your upper or lower back, upper arm, or chest. Do not put the patch over rashes, cuts, or irritated skin. Do not apply to the same area for 14 days.
How often do I change Rivastigmine Patch?
Change the patch every 24 hours around the same time.
What should I avoid while taking?
Avoid abruptly discontinue the medication.
What happen if I overdose?
Contact your primary care doctor. If emergency situation, call 999
What happen if I miss a dose?
Take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
