rivastigmine tartrate

Action

Unknown. Thought to enhance cholinergic function by elevating acetylcholine levels in brain through reversible inhibition of its hydrolysis by cholinesterase.

Availability

Capsules: 1.5 mg, 3 mg, 4.5 mg, 6 mg

Oral solution: 2 mg/ml

Transdermal patch: 4.6 mg/24 hours, 9.5 mg/24 hours

Indications and dosages

➣ Mild to moderate dementia of Alzheimer's disease

Adults: Initially, 1.5 mg P.O. b.i.d. May increase to 3 mg b.i.d. after 2 weeks; may increase further to 4.5 mg b.i.d. and 6 mg b.i.d., if tolerated, after 2 weeks at previous dosage. Typical effective range is 6 to 12 mg/day, up to a maximum of 12 mg/day. Or initially, apply one 4.6-mg patch to the skin q 24 hours. After minimum of 4 weeks, may increase to maintenance dose of one 9.5-mg patch applied to the skin q 24 hours.

➣ Mild to moderate dementia of Parkinson's disease

Adults: Initially, 1.5 mg P.O. b.i.d. May increase to 3 mg b.i.d. after 2 weeks; may increase further to 4.5 mg b.i.d. and 6 mg b.i.d. if tolerated, after 4 weeks at previous dosage. Typical effective range is 3 to 12 mg/day, up to a maximum of 12 mg/day. Or initially, apply one 4.6-mg patch to the skin q 24 hours. After minimum of 4 weeks, may increase to maintenance dose of one 9.5-mg patch applied to the skin q 24 hours.

Off-label uses

• Huntington's disease

Contraindications

• Hypersensitivity to drug, its components, or carbamate derivatives

Precautions

Use cautiously in:

• renal or hepatic impairment, diabetes mellitus, obstructive pulmonary disease, neurologic conditions that can cause seizures, peptic ulcers, GI bleeding, supraventricular conduction disorders

• patients older than age 85

• pregnant patients.

Administration

• Give with food in morning and evening.

Adverse reactions

CNS: depression, dizziness, headache, confusion, insomnia, psychosis, hallucinations, anxiety, tremor, drowsiness, fatigue, syncope, asthenia

CV: chest pain, hypertension, peripheral edema

EENT: rhinitis, pharyngitis

GI: nausea, vomiting, diarrhea, constipation, abdominal pain, flatulence, eructation, dyspepsia, anorexia

GU: urinary tract infection, urinary incontinence

Musculoskeletal: back pain, joint pain, bone fractures

Respiratory: upper respiratory infection, cough, bronchitis

Skin: rash, diaphoresis

Other: weight loss, pain, flulike symptoms

Interactions

Drug-drug. Anticholinergics: interference with anticholinergic effects

Cholinergic agonists (such as bethanechol), succinylcholine and similar neuromuscular blockers: synergistic effects

Drug-herbs. S-adenosylmethionine (SAM-e), St. John's wort: increased risk of serotonin syndrome

Drug-behaviors. Nicotine use: increased drug clearance

Patient monitoring

• Monitor patient's nutritional and hydration status, especially at start of therapy.

• Assess vital signs and cardiovascular status. Stay alert for chest pain and peripheral edema.

• Closely monitor cognitive status, particularly memory. Report significant decline or improvement.

• Assess temperature. Watch for fever and other signs and symptoms ofinfection.

Patient teaching

• Instruct caregiver to give with food in morning and evening.

• Instruct caregiver to use dosing syringe provided with oral solution to withdraw prescribed amount of solution from container; patient may swallow directly from syringe. Or, drug may be mixed with a small glass of water, cold fruit juice, or soda; stir mixture and have patient drink entire amount.

• Instruct caregiver how to apply transdermal patch.

• Inform caregiver that drug initially may worsen CNS impairment. Recommend appropriate safety measures.

• Tell caregiver that memory improvement generally is subtle and that drug works by preventing further memory loss.

• Inform caregiver that drug commonly causes nausea, vomiting, decreased appetite, and weight loss, especially at start of therapy.

• Advise caregiver to watch for and report weight loss, dehydration, and signs and symptoms of GI bleeding.

• Tell caregiver that drug interacts with many over-the-counter products and nicotine. Advise him to discuss these products with prescriber before giving to patient.

• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, herbs, and behaviors mentioned above.