Antitussives: Codeine & Dextromethorphan

• Antitussives, or cough suppressants, manage chronic, nonproductive coughing, frequently linked to allergies or upper respiratory infections.

Prototype Medications

• Codeine (opioid) and dextromethorphan (nonopioid) are two prototype antitussive medications.
• Benzonatate is another nonopioid antitussive medication.

Pharmacologic Action

• Opioid and nonopioid antitussives suppress the cough reflex in the brain.

Adverse Drug Reactions

• Opiates cause CNS depression, leading to common side effects like drowsiness and sedation. These effects are less likely with nonopioid antitussives unless taken in large doses or with other CNS depressants.
• Opioid antitussives can cause dizziness, lightheadedness, nausea, vomiting, constipation, and respiratory depression from CNS depression.
• Both opioid and nonopioid antitussives carry a potential for abuse, so use should be monitored and limited to short durations.

Interventions

• Monitor clients on opioid antitussives for dizziness and lightheadedness when changing positions.
• Administer antitussives with food or milk to prevent gastrointestinal distress, and only when needed to avoid potential abuse.
• Encourage a diet high in fluids and fiber to prevent constipation.
• Closely monitor the respiratory rate of all clients taking opiates. Stop medication if it drops below 12 breaths per minute and stimulate breathing.
• If a client’s oxygen saturation level falls below the acceptable value, administer a reversal medication such as naloxone.

Administration

• Use antitussives short-term and at the lowest effective dose, only when needed.

Client Instructions

• Change positions slowly and sit or lie down if feeling lightheaded.
• Take medication with food or milk if gastrointestinal distress occurs, and lie down if nauseated.
• Increase daily intake of fluids and fiber to prevent constipation when taking opioid antitussives.
• Only take antitussives when needed, for a short period.
• Remove environmental triggers that cause coughing to reduce the need for medication.
• Antitussives with opioids like codeine can cause sedation, drowsiness, and CNS depression, so avoid activities requiring mental alertness, alcohol, and other CNS depressants.

Contraindications and Precautions

• Antitussives are contraindicated for those with sensitivity to the medication, concurrent use of MAO inhibitors, or selective serotonin reuptake inhibitors (SSRIs).
• Exercise caution in clients with reduced respiratory reserve, a history of substance misuse, and in children or older adults.
• Opioid antitussives are not recommended for chronic coughs.
• Opioid antitussives may cause urinary retention in men with prostatic hypertrophy. Stop the medication and contact the provider if this occurs.

Interactions

• Combining alcohol and other CNS depressants with opioid antitussives increases CNS-depressant effects.
• Nonopioid antitussives may increase the analgesic effects of opioids.
• Fever and hypotension may occur if nonopioid antitussives are taken with MAOI antidepressants.
• St. John’s wort may increase sedation caused by opioid antitussives.

Review Questions

• Emphysema is a contraindication for taking codeine.
• Clients taking dextromethorphan should be monitored due to the potential for medication misuse.

Antitussives, including codeine and dextromethorphan, are used to manage chronic, nonproductive coughing. Opioid and nonopioid antitussives suppress the cough reflex in the brain. Monitor for CNS depression and respiratory issues.