Benadryl Allergy / Cold (Acetaminophen / Diphenhydramine / Phenylephrine Tablets)

• If you have an allergy to acetaminophen, diphenhydramine, phenylephrine, or any other part of Benadryl Allergy/Cold (acetaminophen/diphenhydramine/phenylephrine tablets).
• If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
• If you have taken certain drugs used for low mood (depression) like isocarboxazid, phenelzine, or tranylcypromine or drugs used for Parkinson's disease like selegiline or rasagiline in the last 14 days. Taking this medicine within 14 days of those drugs can cause very bad high blood pressure.

This is not a list of all drugs or health problems that interact with Benadryl Allergy/Cold.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

• Tell all of your health care providers that you take Benadryl Allergy/Cold. This includes your doctors, nurses, pharmacists, and dentists.
• Do not take more than what your doctor told you to take. Taking more than you are told may raise your chance of very bad side effects.
• Do not take this medicine for longer than you were told by your doctor.
• Avoid driving and doing other tasks or actions that call for you to be alert until you see how Benadryl Allergy/Cold affects you.
• Avoid drinking alcohol while taking this medicine.
• Talk with your doctor before you use other drugs and natural products that slow your actions.
• Do not use with other products that have diphenhydramine.
• Avoid other sources of acetaminophen. Check labels closely. Too much acetaminophen may cause problems.
• This medicine has acetaminophen in it. Very bad and sometimes deadly liver problems like the need for a liver transplant have happened with acetaminophen use. Most of the time, liver problems have happened in people taking more than 4,000 milligrams of acetaminophen in a day. Also, people who had liver problems were often using more than 1 drug that had acetaminophen in it. Talk with your doctor.
• Call your doctor right away if you take more than 4,000 mg (milligrams) of acetaminophen in a day, even if you feel well.
• If you are taking warfarin, talk with your doctor. You may need to have your blood work checked more closely while you are taking it with Benadryl Allergy/Cold.
• This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take this medicine.
• Use with care in children. Talk with the doctor.
• Different brands of Benadryl Allergy/Cold may have different doses for children. Talk with the doctor before giving this medicine to a child.
• If you are 65 or older, use Benadryl Allergy/Cold with care. You could have more side effects.
• Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using this medicine while you are pregnant.
• Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
• Not able to pass urine or change in how much urine is passed.
• A very bad skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause very bad health problems that may not go away, and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
• Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this medicine, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take Benadryl Allergy/Cold or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Benadryl Allergy/Cold. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Review Date: October 4, 2017

Applies to acetaminophen / diphenhydramine / phenylephrine: oral liquid, oral powder for reconstitution, oral syrup, oral tablet

Cardiovascular

Cardiovascular side effects of acetaminophen have included two cases of hypotension.

Cardiovascular side effects of diphenhydramine have included hypotension, tachycardia, and palpitations.

Cardiovascular side effects of phenylephrine have included palpitations, arrhythmias, and cardiovascular collapse with hypotension.[Ref]

Two cases hypotension have been reported following the administration of acetaminophen. Both patients experienced significant decreases in blood pressure. One of the two patients required pressor agents to maintain adequate mean arterial pressures. Neither episode was associated with symptoms of anaphylaxis. Neither patient was rechallenged after resolution of the initial episode.[Ref]

Dermatologic

Dermatologic side effects have included erythematous skin rashes. Acetaminophen associated bullous erythema and purpura fulminans have also been reported. Acetaminophen has been associated with a risk of rare but potentially fatal serious skin reactions known as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP).[Ref]

Gastrointestinal

One study has suggested that acetaminophen may precipitate acute biliary pain and cholestasis. The mechanism of this effect may be related to inhibition of prostaglandin and alterations in the regulation of the sphincter of Oddi.[Ref]

Gastrointestinal side effects of acetaminophen have included rare cases of acute pancreatitis.

Gastrointestinal side effects of diphenhydramine have included nausea and dry mouth.

Gastrointestinal side effects of phenylephrine have included nausea.[Ref]

Genitourinary

Genitourinary side effects of diphenhydramine have included urinary retention and dysuria.

Genitourinary side effects of phenylephrine have included dysuria.[Ref]

Hematologic

Hematologic side effects of acetaminophen have included rare cases of thrombocytopenia. Methemoglobinemia with resulting cyanosis has also been observed in the setting of acute overdose.

Hematologic side effects of diphenhydramine have rarely included hemolytic anemia, thrombocytopenia, and agranulocytosis.[Ref]

Hepatic

Alcoholic patients may develop hepatotoxicity after even modest doses of acetaminophen. In healthy patients, approximately 15 grams of acetaminophen is necessary to deplete liver glutathione stores by 70% in a 70 kg person. However, hepatotoxicity has been reported following smaller doses. Glutathione concentrations may be repleted by the antidote N-acetylcysteine. One case report has suggested that hypothermia may also be beneficial in decreasing liver damage during overdose.

In a recent retrospective study of 306 patients admitted for acetaminophen overdose, 6.9% had severe liver injury but all recovered. None of the 306 patients died.

A 19 year old female developed hepatotoxicity, reactive plasmacytosis and agranulocytosis followed by a leukemoid reaction after acute acetaminophen toxicity.[Ref]

Hepatic side effects of acetaminophen have included severe and sometimes fatal dose dependent hepatitis in alcoholic patients. Hepatotoxicity has been increased during fasting. Several cases of hepatotoxicity from chronic acetaminophen therapy at therapeutic doses have also been reported despite a lack of risk factors for toxicity.[Ref]

Hypersensitivity

Most commonly, hypersensitivity to diphenhydramine has manifested itself in patients receiving systemic drug after being sensitized to it by topical application. Sensitization with systemic administration has also been reported.[Ref]

Hypersensitivity side effects of acetaminophen have included rare reports of anaphylaxis and fixed drug eruptions.

Hypersensitivity side effects to diphenhydramine have included rash, pruritus and eczema. Photosensitivity reactions have also been reported.[Ref]

Nervous system

The CNS depressant effect of diphenhydramine parallels its plasma concentrations. The plasma concentration threshold for sedation is 30 to 42 ng/mL, and to cause mental impairment is 58 to 74 ng/mL. Patients should be warned against driving while taking diphenhydramine.

Dystonic reactions have been accompanied by dizziness, mental confusion, rigidity, lip and tongue protrusion, trismus, torticollis, and swallowing difficulties and generally resolve spontaneously. Toxic encephalopathy has been reported in a child with chicken pox treated generously with topical diphenhydramine.

Delirium has been reported in elderly patients with mild dementia following a small oral dose of diphenhydramine.[Ref]

Nervous system side effects of diphenhydramine have included depression with drowsiness and sedation in nearly all patients treated. Motor skills may be impaired. Dystonic reactions have been reported after single doses of diphenhydramine.

Nervous system side effects of phenylephrine have included headache, dizziness, nervousness, restlessness, tremor, insomnia, convulsions, and central nervous system depression.[Ref]

Renal

Renal side effects of acetaminophen have included acute tubular necrosis and interstitial nephritis. Adverse renal effects are most often observed after overdose, after chronic abuse (often with multiple analgesics), or in association with acetaminophen-related hepatotoxicity.[Ref]

Acute tubular necrosis usually occurs in conjunction with liver failure, but has been observed as an isolated finding in rare cases. A possible increase in the risk of renal cell carcinoma has been associated with chronic acetaminophen use as well.

A recent case control study of patients with end-stage renal disease suggested that long term consumption of acetaminophen may significantly increase the risk of end-stage renal disease particularly in patients taking more than two pills per day.[Ref]

Respiratory

Respiratory side effects of acetaminophen have included a case of eosinophilic pneumonia.

Respiratory side effects of phenylephrine have included respiratory difficulty.[Ref]

Psychiatric

Psychiatric side effects of phenylephrine have included hallucinations, fear, and anxiety.[Ref]

General

General side effects of phenylephrine have included pallor and weakness.[Ref]

Some side effects of Benadryl Allergy Plus Cold may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.