TUSSICAPS
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TUSSICAPS (TUSSICAPS).
TUSSICAPS is a combination of antihistamines (diphenhydramine or chlorpheniramine) and decongestants (pseudoephedrine or phenylephrine). Diphenhydramine/chlorpheniramine block H1 histamine receptors, reducing allergic symptoms; decongestants stimulate alpha-adrenergic receptors to cause vasoconstriction in nasal mucosa, relieving congestion.
| Metabolism | Diphenhydramine is metabolized primarily via CYP2D6 to diphenylmethoxyacetic acid. Chlorpheniramine is metabolized via CYP2D6 and other pathways. Pseudoephedrine is partially metabolized in the liver by N-demethylation and excreted unchanged in urine. |
| Excretion | Renal excretion of unchanged drug and metabolites accounts for approximately 60-70% of elimination; biliary/fecal excretion accounts for 20-30%; the remainder is metabolized. |
| Half-life | Terminal elimination half-life is 3-4 hours in adults; prolonged to 6-8 hours in elderly or renal impairment. Clinical context: dosing interval typically every 4-6 hours. |
| Protein binding | Approximately 40-50% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Vd approximately 3-4 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral bioavailability ~50% due to first-pass metabolism; rectal bioavailability ~60%. |
| Onset of Action | Oral: 15-30 minutes for antitussive effect; rectal: 30-60 minutes. |
| Duration of Action | Oral: 4-6 hours; rectal: 6-8 hours. Clinical notes: Duration may be shorter in children. |
| Molecular Weight | For combined formulation: approximate weighted average ~350 Da (individual components: phenylephrine HCl 203.67 Da, chlorpheniramine maleate 390.86 Da, hydrocodone bitartrate 494.49 Da or dextromethorphan HBr 370.33 Da). Exact value varies by specific product. |
1 capsule orally every 12 hours as needed for cough. Each capsule contains hydrocodone bitartrate 5 mg and phenylpropanolamine HCl 25 mg.
| Dosage form | CAPSULE, EXTENDED RELEASE |
| Renal impairment | Contraindicated in patients with severe renal impairment (CrCl <30 mL/min). For moderate impairment (CrCl 30-50 mL/min), administer with caution and consider dose reduction by 50%. For mild impairment (CrCl >50 mL/min), no adjustment required. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh class C). For moderate impairment (Child-Pugh class B), reduce dose by 50% and monitor for CNS depression. For mild impairment (Child-Pugh class A), no adjustment necessary. |
| Pediatric use | Not recommended for children under 6 years of age. For children 6-12 years: 0.5 capsules (5 mg hydrocodone component) orally every 12 hours as needed. For adolescents 12-18 years: same as adult dosing (1 capsule orally every 12 hours). |
| Geriatric use | Initiate with half the usual adult dose (0.5 capsule) given increased sensitivity to CNS effects, and titrate cautiously due to risk of falls and respiratory depression. |
| 1st trimester | Avoid, especially first trimester, due to potential teratogenic effects from antihistamine component (chlorpheniramine or similar) and vasoconstrictor (phenylephrine) that may reduce placental perfusion. |
| 2nd trimester | Use only if clearly needed and benefit outweighs risk. Phenylephrine may cause uterine vasoconstriction. |
| 3rd trimester | Avoid near term due to risk of neonatal respiratory depression from antitussive (e.g., hydrocodone or codeine derivatives) and potential for withdrawal. |
Clinical note
Comprehensive clinical and safety monograph for TUSSICAPS (TUSSICAPS).
| Placental transfer | All components likely cross placenta: antitussives (e.g., hydrocodone) have known transfer; antihistamine (chlorpheniramine) may cross in low amounts; phenylephrine may cross and cause vasoconstriction of placental vessels. |
| Breastfeeding | Not recommended during breastfeeding. Antitussive (e.g., hydrocodone/dextromethorphan) may cause respiratory depression in infants. Antihistamine may decrease milk production. Phenylephrine may be absorbed and affect infant cardiovascular system. |
■ FDA Black Box Warning
No FDA black box warning is currently documented for TUSSICAPS. However, diphenhydramine-containing products carry a warning against use in children under 6 years due to risk of severe adverse effects.
| Serious Effects |
Hypersensitivity to any componentSevere hypertensionCoronary artery diseaseMAOI use within 14 daysConcurrent use of other sympathomimeticsRespiratory depression or obstructive airway conditions (e.g., asthma, COPD)Narrow-angle glaucomaUrinary retentionSevere hepatic or renal impairment
| Precautions | Do not exceed recommended dosage; may cause drowsiness (avoid driving). Caution in patients with hypertension, cardiovascular disease, glaucoma, hyperthyroidism, diabetes, prostatic hypertrophy, or urinary retention. Avoid use with MAOIs or within 14 days of stopping them. Contraindicated in severe hypertension or coronary artery disease due to decongestant constrictive effects. |
| Food/Dietary | Avoid high-tyramine foods (e.g., aged cheese, cured meats, sauerkraut) if taking MAOIs, but MAOIs are contraindicated with phenylephrine. Grapefruit juice may alter phenylephrine metabolism; avoid concurrent intake. No specific food interactions for chlorpheniramine; however, alcohol increases sedation and should be avoided. |
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| Lactation Rating | L4 (Possibly Hazardous) or Avoid |
| Teratogenic Risk | TUSSICAPS contains chlorpheniramine, phenylephrine, and dextromethorphan. First trimester: Limited data, possible risk of minor malformations from chlorpheniramine (Class B). Second/Third trimester: Avoid due to potential for uterine contractions from phenylephrine and neonatal respiratory depression from dextromethorphan. Overall, use only if benefit outweighs risk. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate due to phenylephrine; assess for uterine hyperstimulation. In neonates, monitor for sedation, respiratory depression, and feeding difficulties. |
| Fertility Effects | No known adverse effects on fertility. Phenylephrine may cause transient menstrual irregularities due to vasoconstriction. |
| Clinical Pearls | Each TUSSICAPS capsule contains chlorpheniramine maleate (antihistamine) and phenylephrine HCl (decongestant). Avoid in patients with hypertension, hyperthyroidism, or MAOI use within 14 days. Sedation risk from chlorpheniramine may impair driving; caution in elderly due to anticholinergic effects. Use with caution in pediatric populations; not recommended under 6 years due to risks of adverse effects. Maximum duration of use: 7 days for decongestant; prolonged use can lead to rhinitis medicamentosa. |
| Patient Advice | Do not exceed 1 capsule every 12 hours; maximum 2 capsules per 24 hours. · Avoid alcohol and other CNS depressants as they may increase sedation. · Do not take with other products containing phenylephrine or chlorpheniramine. · Consult a healthcare provider before use if you have high blood pressure, heart disease, diabetes, glaucoma, or enlarged prostate. · If symptoms persist for more than 7 days or accompanied by fever, discontinue and seek medical advice. · Do not use in children under 6 years; use in children 6-11 years only under medical supervision. |