Duohist DH and Levodopa/Carbidopa

• Generic Name: chlorpheniramine / dihydrocodeine / phenylephrine
• Dosage Forms: liquid
• Other Brand Names:

Salicylic acid topical is used to treat many skin disorders, such as acne, dandruff, psoriasis, seborrheic dermatitis of the skin and scalp, calluses, corns, common warts, and plantar warts, depending on the dosage form and strength of the preparation.

This medicine is available without a prescription. Some of these preparations are available only with your doctor's prescription.

• Generic Name: carbidopa / levodopa
• Dosage Forms: n.a.
• Other Brand Names: Parcopa, Rytary, Sinemet, Sinemet CR, Duopa

Levodopa is used for symptomatic treatment of parkinsonian syndrome (e.g., parkinsonism, idiopathic Parkinson disease [paralysis agitans]); also used for postencephalitic parkinsonism and symptomatic parkinsonian syndrome resulting from carbon monoxide intoxication or manganese intoxication.

Carbidopa is used in conjunction with levodopa to inhibit decarboxylation of peripheral levodopa and increase the amount of levodopa available for transport to the brain.

Levodopa (in combination with carbidopa) is the most effective drug for relieving motor symptoms of parkinsonian syndrome and is considered the drug of choice for this use.

Levodopa provides symptomatic relief (e.g., akinesia, rigidity, tremor) and improves functional ability; however, effectiveness decreases over time and most patients develop motor fluctuations and dyskinesias (drug-induced involuntary movements) with long-term use.

Strategies for reducing the risk of motor complications associated with long-term levodopa therapy include adjusting dosage of levodopa, adding adjunctive antiparkinsonian agents (e.g., dopamine agonist [e.g., pramipexole, ropinirole, rotigotine], selective monoamine oxidase [MAO]-B inhibitor [e.g., rasagiline, safinamide, selegiline], catechol-O-methyltransferase [COMT] inhibitor [entacapone, tolcapone], amantadine), or initiating therapy with other antiparkinsonian agents first to delay use of levodopa. Delayed approach is often used in younger patients who have a higher risk of developing motor complications. Levodopa generally is used for initial therapy in patients >70 years of age, those with cognitive impairment, and those with severe disease.

Not effective in the management of extrapyramidal effects induced by antipsychotic agents (e.g., phenothiazines).