Carbidopa + Entacapone + Levodopa

Indications

Carbidopa + Entacapone + Levodopa is used for: Parkinson's disease and 'end of dose' motor fluctuations

Adult Dose

Parkinson's disease Adult: PO: Each tab contains levodopa and carbidopa in a ratio of 4:1 and entacapone 200 mg: Initial: 1 tab/day. Titrate dose according to patient's response. Recommended to take only 1 tab per dose administration. Max: 8 tabs/day. Hepatic impairment: Severe: Contraindicated.

Child Dose

Safety & efficacy not established

Renal Dose

Administration

May be taken with or without food. Keep a consistent diet. A change in diet to foods high in protein may delay levodopa absorption & reduce amount taken up in circulation. Excessive acidity also delays stomach emptying & thus delays levodopa absorption. Fe salts (eg in multivit prep) may also reduce amount of levodopa available to the body. Swallow whole.

Contra Indications

Hypersensitivity. Narrow angle glaucoma. Should not be used in patients with suspicious, undiagnosed skin lesions or a history ot melanoma.

Precautions

Periodic monitoring of hepatic, renal, haematopoietic and CV functions in patients on prolonged therapy. Monitor for changes in IOP in patients with chronic wide-angle glaucoma. Caution when used in patients with biliary obstruction. Caution when interpreting plasma and urine levels of catecholamines and their metabolites. Withdrawal should be gradual. Lactation: not known if excreted in breast milk; use caution

Pregnancy-Lactation

Pregnancy Category: C Lactation: not known if excreted in breast milk; use caution

Interactions

Increased risk of postural hypotension when used concurrently with hypotensive drugs. Severe orthostatic hypotension may result from concurrent usage with MAOIs. Dopamine D2 receptor antagonists, phenytoin or papaverine may reduce the efficacy of levodopa. Iron salts may reduce the bioavailability. Concurrent usage with drugs that interfere with biliary excretion may lead to increased plasma levels of entacapone. May depress prolactin secretion and increase growth hormone levels.

Adverse Effects

Side effects of Carbidopa + Entacapone + Levodopa : >10% Entacapone Dyskinesia (25%), Nausea (14%), Diarrhea (10%), Hyperkinesia (10%), Urine discoloration (10%) 1-10% Entacapone Hypokinesia (9%), dizziness (8%), Fatigue (6%), hallucinations (1-4%), anxiety (2%), somnolence (2%), asthenia (2%), agitation (1%), Increased sweating (2%), Purpura (2%), Abdominal pain (8%), constipation (6%), vomiting (4%), dry mouth (3%), dyspepsia (2%), flatulence (2%), taste perversion (1%), gastritis (1%), Back pain (4%), Dyspnea (3%), Bacterial infection (1%) Frequency Not Defined Levodopa/Carbodopa Edema, Agitation, anxiety, ataxia, bruxism, confusion, daytime somnolence decreased attention span, dyskinesia, dystonia, euphoria, insomnia, fainting, fatigue, increased trembling of hands, insouciance, malaise, memory loss, nightmares, nervousness, restlessness, trismus, vivid dreams, Alopecia, hot flushes, increased &/or dark perspiration, skin eruptions, Abdominal pain & discomfort, burning feeling in tongue, constipation, diarrhea, dysgeusia, dry mouth, dysphagia, hiccups, meteorism, sialorrhea, nausea, weight loss, Muscular spasms, muscular cramp, Hematuria, dark urine, incontinence, priapism, urine retention, Blurred vision, diplopia, dilated pupil, oculogyric problems. Entacapone Postural hypotension, Insomnia, Confusion Potentially Fatal: Rhabdomyolysis.

Mechanism of Action

Levodopa is the metabolic precurosor of dopamine, it crosses the blood-brain barrier and is converted to dopamine in the brain. Carbidopa increases the amount of levodopa that is transported into the CNS by inhibiting the decarboxylation of peripheral levodopa. Entacapone is a selective inhibitor of catechol-o-methyltransferase. Given concurrently, entacapone results in greater and more substained plasma levels of levodopa, leading to greater control of parkinsonism symptoms.