Standard Dosing of Dextromethorphan (Tussin) in Geriatric Patients
For geriatric patients, dextromethorphan (Tussin) should be started at a reduced dose of 10-15 mg every 6-8 hours, with a maximum daily dose of 60 mg, following the "start low, go slow" principle to minimize adverse effects. 1
Dosing Considerations for Elderly Patients
- Elderly patients require lower starting doses of medications due to age-related changes in pharmacokinetics and pharmacodynamics 2
- Initial dosing should follow the "start low, go slow" principle to minimize adverse effects, especially CNS-related side effects 1
- The standard adult dose of dextromethorphan is often too high for geriatric patients and should be reduced 1
- Dextromethorphan in combination with quinidine (as in some formulations) should be used with caution in elderly patients due to increased risk of drug interactions 1
Monitoring and Side Effects
- Monitor for sedation, dizziness, and cognitive effects during treatment 1
- Dextromethorphan can cause dose-dependent CNS effects, which may be more pronounced in elderly patients 1, 2
- Risk of falls is increased with CNS-active medications in elderly patients due to sedation and dizziness 1
- The combination dextromethorphan/quinidine should be used with caution due to limited efficacy in patients with behavioral symptoms of dementia while potentially increasing the risk of falls and drug-drug interactions 1
Duration of Treatment
- Dextromethorphan should be used for the shortest duration necessary to achieve symptom relief 1
- Reassess efficacy regularly to determine if continued treatment is necessary 1
Special Considerations
- Dextromethorphan is primarily metabolized by CYP2D6, which shows reduced activity in some elderly patients, potentially leading to higher plasma concentrations 3
- Elderly patients with renal impairment may require further dose reduction due to potential drug accumulation 2
- Avoid combining dextromethorphan with other CNS depressants or serotonergic medications in elderly patients 1
Efficacy
- Dextromethorphan at a dose of 20 mg has been shown to effectively reduce cough frequency in patients with chronic cough 4
- Dextromethorphan has been found to lower cough intensity to a greater degree than codeine in some studies 4
Common Pitfalls to Avoid
- Prescribing standard adult doses of dextromethorphan to elderly patients increases the risk of adverse effects 1, 2
- Combining dextromethorphan with other medications that have CNS effects should be avoided or done with extreme caution 1
- Extended-release formulations may not be appropriate for elderly patients who need more careful dose titration 1
- Failure to recognize that elderly patients may have altered drug metabolism, leading to higher plasma concentrations and increased risk of side effects 2, 3