Pholcodine

An opioid cough suppressant

Pholcodine
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Pholcodine is an opioid cough suppressant (antitussive) used to treat non-productive cough. It is a morphinan derivative with mild sedative effects and is less potent than codeine.

Pharmacology

Pholcodine acts primarily on the central nervous system (CNS) to suppress the cough reflex. It is believed to exert its effects by binding to opioid receptors in the brain, which leads to a reduction in the cough reflex. Unlike other opioids, pholcodine has minimal analgesic properties and is less likely to cause respiratory depression.

Medical uses

Pholcodine is used in the management of dry coughs associated with upper respiratory tract infections. It is available in various formulations, including syrups, lozenges, and tablets.

Side effects

Common side effects of pholcodine include drowsiness, dizziness, and nausea. It may also cause constipation and dry mouth. Due to its sedative effects, caution is advised when driving or operating machinery.

Contraindications

Pholcodine should not be used in individuals with a known hypersensitivity to the drug or in those with asthma or chronic obstructive pulmonary disease (COPD) due to the risk of respiratory complications.

Interactions

Pholcodine may interact with other CNS depressants, such as alcohol, benzodiazepines, and other opioids, leading to enhanced sedative effects. It is important to avoid concurrent use with these substances.

Regulation

Pholcodine is regulated differently in various countries. In some regions, it is available over-the-counter, while in others, it requires a prescription. Its use is restricted in certain countries due to concerns about potential allergic reactions and anaphylaxis in patients who have been exposed to neuromuscular blocking agents.

Chemistry

Pholcodine is a morphinan derivative with the chemical formula C23H30N2O4. It is structurally related to morphine but has a morpholine ring instead of a phenolic hydroxyl group, which contributes to its distinct pharmacological profile.

History

Pholcodine was first synthesized in the early 20th century and has been used as a cough suppressant for many decades. Its development was part of efforts to find effective antitussives with fewer side effects than morphine and codeine.

Related pages

• Codeine
• Morphine
• Opioid
• Cough suppressant