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Hydromet Side Effects

Generic name: homatropine / hydrocodone

Medically reviewed by Last updated on Apr 3, 2023.

Note: This document contains side effect information about homatropine / hydrocodone. Some dosage forms listed on this page may not apply to the brand name Hydromet.

Applies to homatropine / hydrocodone: oral solution, oral syrup, oral tablet.


Oral route (Tablet; Solution)

Warning: Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; medication errors; cytochrome P450 3A4 interaction; concomitant use with benzodiazepines or other CNS depressants; interaction with alcohol; neonatal opioid withdrawal syndromeAddiction, Abuse, and MisuseHydrocodone bitartrate/homatropine methylbromide exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death. Reserve hydrocodone bitartrate/homatropine methylbromide for use in adult patients for whom the benefits of cough suppression are expected to outweigh the risks, and in whom an adequate assessment of the etiology of the cough has been made. Assess each patient’s risk prior to prescribing hydrocodone bitartrate/homatropine methylbromide, prescribe hydrocodone bitartrate/homatropine methylbromide for the shortest duration that is consistent with individual patient treatment goals, monitor all patients regularly for the development of addiction or abuse, and refill only after reevaluation of the need for continued treatment.Life-Threatening Respiratory DepressionSerious, life-threatening, or fatal respiratory depression may occur with use of hydrocodone bitartrate/homatropine methylbromide. Monitor for respiratory depression, especially during initiation of hydrocodone bitartrate/homatropine methylbromide or when used in patients at higher risk.Accidental IngestionAccidental ingestion of even one dose of hydrocodone bitartrate/homatropine methylbromide, especially by children, can result in a fatal overdose of hydrocodone.Risk of Medication ErrorsEnsure accuracy when prescribing, dispensing, and administering hydrocodone bitartrate/homatropine methylbromide. Dosing errors can result in accidental overdose and death. Always use an accurate milliliter measuring device when measuring and administering hydrocodone bitartrate/homatropine methylbromide.Cytochrome P450 3A4 InteractionThe concomitant use of hydrocodone bitartrate/homatropine methylbromide with all cytochrome P450 3A4 inhibitors may result in an increase in hydrocodone plasma concentrations, which could increase or prolong adverse drug effects and may cause potentially fatal respiratory depression. In addition, discontinuation of a concomitantly used cytochrome P450 3A4 inducer may result in an increase in hydrocodone plasma concentration. Avoid the use of hydrocodone bitartrate/homatropine methylbromide in patients taking a CYP3A4 inhibitor or inducer.Risk from Concomitant Use with Benzodiazepines or Other CNS DepressantsConcomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Avoid the use of hydrocodone bitartrate/homatropine methylbromide in patients taking benzodiazepines, other CNS depressants, or alcohol.Interaction with AlcoholInstruct patients not to consume alcoholic beverages or use prescription or non-prescription products that contain alcohol while taking hydrocodone bitartrate/homatropine methylbromide. The co-ingestion of alcohol with hydrocodone bitartrate/homatropine methylbromide may result in increased plasma levels and a potentially fatal overdose of hydrocodone.Neonatal Opioid Withdrawal SyndromeHydrocodone bitartrate/homatropine methylbromide is not recommended for use in pregnant women. Prolonged use of hydrocodone bitartrate/homatropine methylbromide during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and treated, and requires management according to protocols developed by neonatology experts. If hydrocodone bitartrate/homatropine methylbromide is used for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available.

Oral route (Tablet)

Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Avoid use of opioid cough medications in patients taking benzodiazepines, other CNS depressants, or alcohol.

Serious side effects of Hydromet

Along with its needed effects, homatropine / hydrocodone may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking homatropine / hydrocodone:

More common

Incidence not known

Get emergency help immediately if any of the following symptoms of overdose occur while taking homatropine / hydrocodone:

Symptoms of overdose

Other side effects of Hydromet

Some side effects of homatropine / hydrocodone may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Incidence not known

For Healthcare Professionals

Applies to homatropine / hydrocodone: oral syrup, oral tablet.


The most commonly reported adverse effects have included sedation (somnolence, mental clouding, lethargy) impaired mental and physical performance, lightheadedness, dizziness, headache, dry mouth, nausea, vomiting, and constipation.[Ref]

Nervous system

Frequency not reported: Coma, somnolence, facial dyskinesia, tremor, insomnia, migraine, increased intracranial pressure, seizure, dizziness, decreased mental alertness with impaired mental and/or physical abilities, serotonin syndrome, tinnitus[Ref]

Serotonin syndrome has been reported with concomitant opioids and serotonergic drugs[Ref]


Frequency not reported: Bronchitis, cough, dyspnea, nasal congestion, nasopharyngitis, respiratory depression including fatal respiratory depression, sinusitis, upper respiratory tract infection


Frequency not reported: Increased blood pressure, decreased blood pressure, tachycardia, chest pain, orthostatic hypotension, palpitations, syncope, prolonged QT interval, hot flush, atrial fibrillation, myocardial infarction, arrhythmias including premature ventricular contractions, flushing[Ref]


Frequency not reported: Peripheral edema, death, falling injuries, accidental overdose, neonatal opioid withdrawal syndrome[Ref]


Frequency not reported: Abdominal pain, bowel obstruction, diarrhea, difficulty swallowing, GERD, indigestion, pancreatitis, paralytic ileus, dysgeusia, ischemic colitis, increase of serum amylase, dry mouth, biliary tract spasm (spasm of the sphincter of Oddi)[Ref]


Frequency not reported: Ureteral spasm, spasm of vesicle sphincters, urinary retention, urinary tract infection, hypogonadism, infertility[Ref]


Frequency not reported: Anaphylaxis


Frequency not reported: Hyperhidrosis, rash, pruritus[Ref]


Frequency not reported: Agitation, anxiety, confusion, fear, dysphoria, depression


Adrenal insufficiency has been reported with opioid use, most often following greater than one month of use. Androgen deficiency has been reported with chronic opioid use.

Frequency not reported: Adrenal insufficiency, androgen deficiency


Frequency not reported: Arthralgia, backache, muscle spasm


Frequency not reported: Miosis, visual disturbances


Frequency not reported: Decreased appetite


1. Product Information. Homatropine Methylbromide-Hydrocodone (homatropine-hydrocodone). KVK-Tech Inc. 2017.

2. Fricke J, Halladay SC, Bynum L, Francisco CA. Pain relief after dental impaction surgery using ketorolac, hydrocodone plus acetaminophen, or placebo. Clin Ther. 1993;15:500-9.

3. Sackner MA. Effects of hydrocodone bitartrate on breathing pattern of patients with chronic obstructive pulmonary disease and restrictive lung disease. Mt Sinai J Med. 1984;51:222-6.

4. Product Information. Hycodan (homatropine-hydrocodone). Endo Laboratories LLC. 2001;PROD.

5. Morrison AB. Toxicity and abuse of hydrocodone bitartrate. Can Med Assoc J. 1979;120:1338.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.