rivastigmine (Exelon, Exelon Patch)

Dosing and uses of Exelon (rivastigmine)

• Adult
• Pediatric

 

Adult dosage forms and strengths

capsule

• 1.5mg
• 3mg
• 4.5mg
• 6mg

transdermal patch

• 4.6mg/24hr
• 9.5mg/24hr
• 13.3mg/24hr

 

Alzheimer Dementia

OraL

• Indicated for mild-to-moderate dementia of the Alzheimer's type
• Initial: 1.5 mg PO q12hr
• Increase by 1.5 mg/dose q2Weeks; not to exceed 6 mg PO q12hr
• Maintenance: 3-6 mg PO q12hr (higher end may be more beneficial)

TransdermaL

• Indicated for mild, moderate, and severe dementia of the Alzheimer's type
• Initial: Apply 4.6 mg q24hr
• Dose titration: May increase dose to 9.5 mg q24hr after a minimum 4 weeks if well tolerated; after an additional 4 weeks, may further increase to 13.3 mg patch if needed
• Mild-to-moderate Alzheimer disease: Effective dosage range is 9.5-13.3 mg/24 hr
• Moderate-to-severe Alzheimer disease: Effective dose is 13.3 mg/24 hr
• Replace with new patch q24hr

 

Parkinson Dementia

OraL

• Initial: 1.5 mg PO q12hr
• Increase by 1.5 mg/dose q4Weeks; not to exceed 6 mg PO q12hr
• Maintenance: 1.5-6 mg PO q12hr

TransdermaL

• Initial: Apply 4.6 mg q24hr
• May increase dose to 9.5 mg q24hr after a minimum 4 weeks if well tolerated; after an additional 4 weeks, may further increase to 13.3 mg patch if needed

 

Dosage modifications

TransdermaL

• Renal impairment: No dosage adjustment required
• Mild-to-moderate hepatic impairment: Not to exceed 4.6 mg q24hr
• Low body weight (<50 kg): Carefully titrate and monitor patients with low body weight for toxicities (eg, excessive nausea, vomiting), and consider reducing maintenance dose to 4.6 mg q24hr if toxicity develops

 

Administration

Take with food

Oral solution may be swallowed directly from provided syringe or mixed with small glass of fluid

Switching from oral to transdermaL

• If PO dose <6 mg/day, switch to 4.6 mg/24 hr patch
• If PO dose is 6-12 mg/day, switch to 9.5 mg/24 hr patch

 

Pediatric dosage forms and strengths

Not applicable

 

Exelon (rivastigmine) adverse (side) effects

>10%

Nausea (PO 47%; patch 21%)

Vomiting (PO 31%; patch 6-19%)

Dizziness (PO 21%; patch 2-7%)

Diarrhea (PO 19%; patch 6-10%)

Headache (PO 17%; patch 3-4%)

Anorexia (PO 17%; patch 3-9%)

Abdominal pain (PO 13%; patch 2-4%)

 

1-10%

Decreased weight (3-8%)

Insomnia (PO 9%; patch 1-4%)

Anxiety (PO 5%; patch 3%)

Asthenia (PO 6%; patch 2-3%)

Vertigo (2%)

Fatigue (2%)

 

Warnings

Contraindications

Hypersensitivity to rivastigmine or carbamates

History of application site reaction with transdermal patch

Active GI bleeding

 

Cautions

Anorexia

Sick sinus syndrome

History of peptic ulcer

History of asthma/COPd

May induce/exacerbate extrapyramidal symptoms

Concomitant NSAId

Gastrointestinal adverse reactions may include significant nausea, vomiting, diarrhea, anorexia/decreased appetite, and weight loss, and may necessitate treatment interruption; dehydration may result from prolonged vomiting or diarrhea and can be associated with serious outcomes

Medication errors with transdermal patches have resulted in serious adverse events; some cases have required hospitalization, and in rare instances, medication errors have led to death; most of the errors have involved not removing the old patch when putting on a new one and the use of multiple patches at the same time

Skin application site reactions may occur with transdermal application and are usually mild or moderate in intensity; these reactions are not in themselves an indication of sensitization; however, use of rivastigmine patch may lead to allergic contact dermatitis

Isolated postmarketing reports of disseminated hypersensitivity reactions of the skin irrespective of the administration route (oral or transdermal); treatment should be discontinued if disseminated hypersensitivity reaction of the skin occurs

 

Pregnancy and lactation

Pregnancy category: B

Lactation: Unknown if excreted in milk; not recommended

 

Pregnancy categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

 

Pharmacology of Exelon (rivastigmine)

Mechanism of action

Reversible acetylcholinesterase inhibitor that causes an increase in concentrations of acetylcholine, which in turn enhances cholinergic neurotransmission

 

Absorption

Bioavailability: 36% (PO)

Duration: 10 hr (PO); 24 hr (patch)

Peak plasma time: 1 hr (PO); 8 hr (patch)

 

Distribution

Protein bound: 40%

Vd: 1.8-2.7 L/kg

 

Metabolism

Metabolized by cholinesterase

 

Elimination

Half-life: 1.5 hr (PO), 3 hr (patch)

Total body clearance: 1.2-2.4 L/min

Excretion: Urine (97%)