Alcohol and Medications
By: S. Rennie, LPN
Alcohol interactions can occur with not only prescribed medications, but also over-the-counter (OTC) medications – such as anti-histamines and pain relievers – and some herbal preparations – chamomile, valerian, lavender. Alcohol alone can cause drowsiness or a lightheaded feeling. Some medications taken with alcohol can intensify these reactions and put people at risk for accidents, falls, or sometimes, even death.1 These interactions can have varying affects, depending on the timing of consumption of each.1,2
Alcohol and medication interactions fall into two general categories: Pharmacokinetic and Pharmacodynamic.
Pharmacokinetic interactions are those where alcohol directly interferes with the normal metabolism of the medication. This interference can be as follows:
- The breakdown and excretion of the affected medications are delayed, because the medications must compete with alcohol for breakdown by cytochrome P450. This type of interaction has been described mostly for metabolic
reactions involving CYP2E1, but it also may involve CYP3A4 and CYP1A2 (Salmela et al. 1998).2 (p.48)
- The metabolism of the affected medications is accelerated, because alcohol enhances the activity of medication-metabolizing cytochromes. When alcohol is not present simultaneously to compete for the cytochromes, increased cytochrome activity results in an increased elimination rate for medications that these enzymes metabolize.2 (p.48)
Pharmacodynamic alcohol-medication interactions are additive effects of the combination. This interaction most commonly happens in the central nervous system. The effects of the medication is altered by alcohol, but the concentration of the medication in the blood stays the same. As with barbiturates and benzodiazepines, for example, the interaction can be synergistic – the effects of the combination is more than the effects of each one individually. Alcohol enhances the sedative effects of other medications such as antihistamines and anti-depressants.2
Some interactions are as follows:
Alcohol/Antibiotic Interaction: Even though most antibiotics have warnings to avoid alcohol while taking them, only a few appear to have interactions. Erythromycin may increase absorption of alcohol in the intestine by speeding up gastric empyting. Alcohol should not be consumed when taking isoniazid because the isoniazid alone can cause liver damage, alcohol in conjunction with will exacerbate it. Intense vomiting, nausea, cramping, flushing and accelerated heartbeat can occur when alcohol is combined with metronidazole and tinidazole, and it is recommended to wait 72 hours before alcohol consumption. Moderate alcohol consumption doesn't interfere with the effectiveness of the antibiotic. But research indicates that heavy alcohol consumption can impair certain immune cell functions and the alcohol-dependent person is more at risk for certain infections.2,3
Tricyclic antidepressants. This class of antidepressant (i.e., amitriptyline, doxepin, maprotiline, and trimipramine) has a higher sedative-to-stimulant ratio, which causes the most sedation, than the other antidepressant classes. Alcohol causes a pharmacodynamic interaction that increases sedative effect of TCAs. Pharmacokinetic interactions can also occur when alcohol interferes with the liver metabolism of the TCA. This can cause increased levels of the TCA in the bloodstream. Convulsions and disturbances in heart rhythm can result from high TCA levels.2
Selective serotonin reuptake inhibitors. The most commonly used antidepressants are in the SSRI family (i.e., fluvoxamine, fluoxetine, paroxetine, and sertraline). They have much less of a sedating effect and there seem to be no serious interactions when combined with moderate alcohol consumption. (Matilla, 1990) SSRIs also have the best safety profile when combined with large quantities of alcohol, such as in an attempted suicide situation.2
Monoamine oxidase inhibitors and atypical antidepressants. Combining alcohol with MAOIs (e.g., phenelzine and tranylcypromine) or atypical antidepressants can cause adverse effects. The MAOI/tyramine combination can cause severe high blood pressure. Tyramine is found in red wines, so special precautions should be taken to avoid it. Enhanced sedation can occur when alcohol is combined with atypical antidepressants.2
Antihistamines: Used to treat allergies and colds, antihistamines are available both OTC and by prescription and can cause drowsiness, sedation and low blood pressure, especially in elderly patients. (Dufour et al. 1992) The sedating effects of antihistamines can be increased through pharmacodynamic interactions. Although newer antihistamines (i.e., certrizine and loratidine) minimize drowsiness, they may still increase low blood pressure, especially in combination with alcohol.2
Barbiturates: These medications are sedative or sleep-inducing (sedative-hypnotic) medications frequently used as anesthetics. The most commonly prescribed barbiturate is phenobarbital, which is used to treat seizure disorders. A pharmacodynamic interaction results when combining phenobarbital with alcohol because it activates some of the same CNS molecules. This causes a synergistic enhancement of the sedative properties of the barbiturate. Because alcohol inhibits the breakdown of phenobarbital in the liver, a pharmacokinetic interaction occurs which slows the metabolism and may increase the level of phenobarbital in the blood.
Benzodiazepines. BZDs are another sedative-hypnotic and act through the same molecules of the brain as barbiturates. Thus the same synergistic enhancements of sedation occur with concurrent BZD and moderate alcohol consumption. Barbiturates and BZDs each may impair the memory, but when used with alcohol, the effect is exacerbated. In fact, this
effect sometimes is exploited by mixing alcoholic beverages with BZDs, such as the rapid-acting flunitrazepam (Rohypnol®), an agent implicated in date rape (Simmons and Cupp 1998).2
Muscle Relaxants: Several muscle relaxants (e.g., carisoprodol, cyclobenzaprine, and baclofen), may cause a narcotic-type reaction when taken with alcohol. The effects includes dizziness, weakness, agitation, confusion and euphoria.2
Nonnarcotic Pain Medications and Anti-Inflammatory Agents: These include aspirin, acetaminophen, ibuprofen and the nonsteroidal anti-inflammatory medications such as naproxen, indomethacin, and diclofenac.
Alcohol may exacerbate the increased risk of ulcers and GI bleeding in the elderly that NSAIDs have been connected with. Aspirin, indomethacin, and ibuprofen cause prolonged bleeding by inhibiting the function of certain blood cells involved in blood clot formation. This effect also appears to be enhanced by concurrent alcohol use (Deykin et al. 1982).
A combination of alcohol and acetaminophen may result in an increased risk of acetaminophen-related toxicity to the liver.
Combination cough, cold, and flu medications may contain aspirin, acetaminophen, or ibuprofen, which could contribute to serious health consequences when combined with alcohol.2
Opioids. Opioids are commonly used for treating pain and have sedative properties along with the analgesia. Alcohol accentuates the sedating effects of opiods. Large consumption of alcohol and opioids together can be lethal because it not only causes respiratory depression, but also reduces the cough reflex. There are some opioid medications that also contain acetaminophen (i.e., hydrocodone, codeine), which can cause acetaminophen-related toxicity to the liver.2
On pages 4-8 in the following PDF is a chart of "Commonly Used Medicines (Both Prescription and Over-the-Counter) That Interact with Alcohol"
Harmful Interactions: Mixing Alcohol with Medicines. National Institutes on Alcohol Abuse and Alcoholism. NIH Publication No. 03-5329. Revised 2007. http://pubs.niaaa.nih.gov/publications/Medicine/Harmful_Interactions.pdf
- Ron Weathermon, Pharm.D., Daid W. Crabb, MD. Alcohol and Medication Interactions. Alcohol Research & Health. Vol. 23, No. 1, pages 40-54. 1999. http://pubs.niaaa.nih.gov/publications/arh23-1/40-54.pdf
- Molly Webster, Is it true that you shouldn't drink while on antibiotics? Scienceline. October 30, 2006.
Salmela, K.S.; Kessova, I.G.; Tsyrlov, I.B.; and Lieber, C.S. Respective roles of human cytochrome P-4502E1, 1A2, and 3A4 in the hepatic microsomal ethanol oxidizing system. Alcoholism: Clinical and Experimental Research 22:2125–2132, 1998.
Mattila, M.J. Alcohol and drug interactions. Annals of Medicine 22:363–369, 1990.
Dufour, M.C.; Archer, L.; and Gordis, E. Alcohol and the elderly. Clinical Geriatric Medicine. 8:127–141, 1992.
Simmons, M.M., and Cupp, M.J. Use and abuse of flunitrazepam. Annals of Pharmacotherapy. 32:117–119, 1998.
Deykin, D.; Janson, P.; and McMahon, L. Ethanol potentiation of aspirin-induced prolongation\ of the bleeding time. New England Journal of Medicine 306:852–854, 1982.
This page was last modified on : 08/21/2009