Tus%25252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520qd

Tus%25252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520qd is a combination product, typically containing dextromethorphan (a cough suppressant) and guaifenesin (an expectorant). ## Overview Dextromethorphan acts centrally on the cough center in the medulla. Guaifenesin increases the output of respiratory tract fluid, making mucus less viscous and easier to expectorate. ## Primary Indications * Symptom relief of cough and chest congestion associated with the common cold, bronchitis, or other respiratory conditions. ## Adult Dosing Dosage varies widely based on specific product formulation (e.g., immediate-release, extended-release, liquid, tablet). Common dosages for dextromethorphan range from 10-20 mg every 4-6 hours or 60 mg extended-release every 12 hours. Common dosages for guaifenesin range from 200-400 mg every 4 hours or 600-1200 mg extended-release every 12 hours. **Always consult the specific product labeling.** Maximum daily doses for dextromethorphan are typically 120 mg for immediate-release formulations. ## Pediatric Dosing Dextromethorphan dosing in pediatrics is weight-based and varies by age. Generally, for children 6 to <12 years: 5-10 mg every 4-6 hours, not to exceed 30 mg in 24 hours. For children 12 years and older: 10-20 mg every 4-6 hours, not to exceed 120 mg in 24 hours. Guaifenesin dosing in pediatrics is also age and weight-dependent. **Specific pediatric dosing requires careful review of the product's prescribing information and may depend on local guidelines or pediatrician's recommendation.** Products are generally not recommended for children under 4 or 6 years of age unless specifically directed by a healthcare provider. ## Dose Adjustments No specific dose adjustments are typically required for renal or hepatic impairment for dextromethorphan and guaifenesin at standard doses. However, caution is advised in patients with severe impairment, and **consulting product literature or a healthcare professional is recommended.** ## Contraindications * Hypersensitivity to dextromethorphan or guaifenesin. * Use within 14 days of MAO inhibitors or within 14 days of stopping an MAO inhibitor due to risk of hypertensive crisis with dextromethorphan. * Use in patients with significant respiratory compromise (e.g., asthma, emphysema) where mucus expectoration is crucial, as cough suppression could be detrimental. ## Adverse Effects * **Dextromethorphan:** Dizziness, drowsiness, nausea, vomiting, constipation. Higher doses can cause confusion, hallucinations, respiratory depression, and serotonin syndrome (especially when combined with other serotonergic agents). * **Guaifenesin:** Nausea, vomiting, dizziness, headache, rash. ## Key Drug Interactions * **Dextromethorphan:** * MAO inhibitors: Risk of hypertensive crisis. * Serotonergic agents (SSRIs, SNRIs, triptans, tramadol): Risk of serotonin syndrome. * CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine): May increase dextromethorphan plasma concentrations, increasing risk of toxicity. * Alcohol and other CNS depressants: Additive CNS depression. * **Guaifenesin:** Generally few significant drug interactions. ## Monitoring * Monitor for effectiveness in suppressing cough and aiding expectoration. * Monitor for adverse effects, particularly CNS depression, dizziness, and signs of serotonin syndrome. * Assess for underlying conditions that may be masked or worsened by cough suppression. ## Clinical Pearls * Dextromethorphan is an NMDA receptor antagonist and has potential for abuse at supra-therapeutic doses. * Guaifenesin is most effective when patients are well-hydrated. * Ensure the correct product formulation is used to achieve the desired duration of action and avoid accidental overdose. * Combination products can make it difficult to dose each component appropriately if titration or specific dosing for one agent is required. *** *This information is intended for healthcare professionals. Always verify current prescribing information and consult with a qualified healthcare provider for any specific medical advice or treatment decisions. Pediatric dosing and product availability can vary significantly.*