Side Effects > Diphenhydramine

Diphenhydramine Side Effects

Brand Names: Simply Sleep, Sominex, Dytuss, Benadryl Allergy, Ben-Tann, Benadryl, Nervine

Please note - some side effects for Diphenhydramine may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

For the consumer Diphenhydramine/Phenylephrine Diphenhydramine Diphenhydramine/Ibuprofen Diphenhydramine/Pseudoephedrine Diphenhydramine Chewable Tablets Diphenhydramine/Phenylephrine Chewable Tablets Diphenhydramine/Pseudoephedrine Controlled-Release Capsules Diphenhydramine Cream Diphenhydramine Dispersible Tablets Diphenhydramine Elixir Diphenhydramine/Pseudoephedrine Liquid Diphenhydramine/Phenylephrine Liquid Diphenhydramine Lotion Diphenhydramine Orally Disintegrating Strips Diphenhydramine Solution Diphenhydramine Suspension Diphenhydramine/Phenylephrine Suspension Diphenhydramine/Hydrocodone/Phenylephrine Syrup For the professional Diphenhydramine Diphenhydramine Capsules Diphenhydramine Injection Diphenhydramine Injection USP Diphenhydramine Injection, USP

Side Effects of Diphenhydramine - for the consumer

Diphenhydramine/Phenylephrine

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Phenylephrine:

Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability (especially in children); headache; loss of appetite; nausea; nervousness; restlessness; trouble sleeping; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Phenylephrine:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; chest pain; decreased coordination; difficulty urinating; fast or irregular heartbeat; fever; hallucinations; seizure; severe dizziness or drowsiness; severe nervousness, anxiety, restlessness, or trouble sleeping; tremors; unusual weakness.

Diphenhydramine

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine:

Dizziness; drowsiness; dry mouth, throat, and nose; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; decreased alertness; excitability; fast heartbeat; hallucinations; tightness or pounding in the chest; tremor; wheezing.

Diphenhydramine/Ibuprofen

All medicines can cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Ibuprofen:

Constipation; diarrhea; dizziness; drowsiness; dry mouth, throat, and nose; excitability; gas; headache; heartburn; nausea; stomach pain or upset; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Ibuprofen:

Severe allergic reactions (rash; hives; itching; trouble breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody or black, tarry stools; change in the amount of urine produced; chest pain; confusion; dark urine; depression; fainting; fast or irregular heartbeat; fever, chills, or persistent sore throat; hallucinations; mental or mood changes; numbness of an arm or leg; one-sided weakness; red, swollen, blistered, or peeling skin; ringing in the ears; seizures; severe headache or dizziness; severe or persistent stomach pain or nausea; severe vomiting; shortness of breath; stiff neck; sudden or unexplained weight gain; swelling of hands, legs, or feet; tremor; unusual bruising or bleeding; unusual joint or muscle pain; unusual tiredness or weakness; vision or speech changes; vomit that looks like coffee grounds; wheezing; yellowing of the skin or eyes.

Diphenhydramine/Pseudoephedrine

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Pseudoephedrine:

Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability (especially in children); headache; loss of appetite; nausea; nervousness; restlessness; trouble sleeping; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Pseudoephedrine:

Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; chest pain; decreased coordination; difficulty urinating; fast or irregular heartbeat; fever; hallucinations; seizure; severe dizziness and drowsiness; severe nervousness, anxiety, or restlessness; tremors; unusual weakness.

Diphenhydramine Chewable Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine Chewable Tablets:

Dizziness; drowsiness; dry mouth, throat, and nose; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine Chewable Tablets:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; decreased alertness; excitability; fast heartbeat; hallucinations; tightness or pounding in the chest; tremor; wheezing.

Diphenhydramine/Phenylephrine Chewable Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Phenylephrine Chewable Tablets:

Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability (especially in children); headache; loss of appetite; nausea; nervousness; restlessness; trouble sleeping; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Phenylephrine Chewable Tablets:

Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; chest pain; decreased coordination; difficulty urinating; fast or irregular heartbeat; fever; hallucinations; seizure; severe dizziness and drowsiness; severe nervousness, anxiety, or restlessness; tremors; unusual weakness.

Diphenhydramine/Pseudoephedrine Controlled-Release Capsules

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Pseudoephedrine Controlled-Release Capsules:

Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability (especially in children); headache; loss of appetite; nausea; nervousness; restlessness; trouble sleeping; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Pseudoephedrine Controlled-Release Capsules:

Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; chest pain; decreased coordination; difficulty urinating; fast or irregular heartbeat; fever; hallucinations; seizure; severe dizziness and drowsiness; severe nervousness, anxiety, or restlessness; tremors; unusual weakness.

Diphenhydramine Cream

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine Cream:

Skin irritation.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine Cream:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue).

Diphenhydramine Dispersible Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine Dispersible Tablets:

Dizziness; drowsiness; dry mouth, throat, and nose; excitability; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine Dispersible Tablets:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; fast heartbeat or pounding in the chest; decreased alertness; hallucinations; tremor; wheezing.

Diphenhydramine Elixir

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine Elixir:

Dizziness; drowsiness; dry mouth, throat, and nose; excitability; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine Elixir:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; fast heartbeat or pounding in the chest; decreased alertness; hallucinations; tremor; wheezing.

Diphenhydramine/Pseudoephedrine Liquid

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Pseudoephedrine Liquid:

Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability (especially in children); headache; loss of appetite; nausea; nervousness; restlessness; trouble sleeping; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Pseudoephedrine Liquid:

Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; chest pain; decreased coordination; difficulty urinating; fast or irregular heartbeat; fever; hallucinations; seizure; severe dizziness and drowsiness; severe nervousness, anxiety, or restlessness; tremors; unusual weakness.

Diphenhydramine/Phenylephrine Liquid

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Phenylephrine Liquid:

Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability (especially in children); headache; loss of appetite; nausea; nervousness; restlessness; trouble sleeping; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Phenylephrine Liquid:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; chest pain; decreased coordination; difficulty urinating; fast or irregular heartbeat; fever; hallucinations; seizure; severe dizziness or drowsiness; severe nervousness, anxiety, or restlessness; tremors; unusual weakness.

Diphenhydramine Lotion

All medicines may cause side effects, but many people have no, or minor side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine Lotion:

Skin irritation.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine Lotion:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue).

Diphenhydramine Orally Disintegrating Strips

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine Orally Disintegrating Strips:

Dizziness; drowsiness; dry mouth, throat, and nose; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine Orally Disintegrating Strips:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; decreased alertness; excitability; fast heartbeat; hallucinations; tightness or pounding in the chest; tremor; wheezing.

Diphenhydramine Solution

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine Solution:

Dizziness; drowsiness; dry mouth, throat, and nose; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine Solution:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; decreased alertness; excitability; fast heartbeat; hallucinations; pain, redness, or swelling at the injection site; tightness or pounding in the chest; tremor; wheezing.

Diphenhydramine Suspension

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine Suspension:

Dizziness; drowsiness; itching; dry mouth, throat, and nose; excitability; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine Suspension:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; fast heartbeat or pounding in the chest; decreased alertness; hallucinations; tremor; wheezing.

Diphenhydramine/Phenylephrine Suspension

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Phenylephrine Suspension:

Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability (especially in children); headache; loss of appetite; nausea; nervousness; restlessness; trouble sleeping; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Phenylephrine Suspension:

Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; chest pain; decreased coordination; difficulty urinating; fast or irregular heartbeat; fever; hallucinations; seizure; severe dizziness and drowsiness; severe nervousness, anxiety, or restlessness; tremors; unusual weakness.

Diphenhydramine/Hydrocodone/Phenylephrine Syrup

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Diphenhydramine/Hydrocodone/Phenylephrine Syrup:

Dizziness; drowsiness, excitability; headache; nausea; nervousness or anxiety; trouble sleeping; weakness.

Seek medical attention right away if any of these SEVERE side effects occur when using Diphenhydramine/Hydrocodone/Phenylephrine Syrup:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); difficulty urinating; fast or irregular heartbeat; hallucinations; seizures; severe dizziness, lightheadedness, or headache; severe drowsiness; tremor.

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For the professional

Diphenhydramine

The most frequent adverse reactions are underscored.

1. General: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of the mouth, nose and throat.
2. Cardiovascular System: Hypotension, headache, palpitations, tachycardia, extrasystoles.
3. Hematologic System: Hemolytic anemia, thrombocytopenia, agranulocytosis.
4. Nervous System: Sedation, sleepiness, dizziness, disturbed coordination, fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, neuritis, convulsions.
5. GI System: Epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation.
6. GU System: Urinary frequency, difficult urination, urinary retention, early menses.
7. Respiratory System: Thickening of bronchial secretions, tightness of chest and wheezing, nasal stuffiness.

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Diphenhydramine Capsules

The most frequent adverse reactions are underscored.

1. General: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of mouth, nose and throat.
2. Cardiovascular System: Hypotension, headache, palpitations, tachycardia, extrasystoles.
3. Hematologic System: Hemolytic anemia, thrombocytopenia, agranulocytosis.
4. Nervous System:Sedation, sleepiness, dizziness, disturbed coordination, fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, neuritis, convulsions.
5. GI System:Epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation.
6. GU System: Urinary frequency, difficult urination, urinary retention, early menses.
7. Respiratory System:Thickening of bronchial secretions, tightness of chest and wheezing, nasal stuffiness.

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Diphenhydramine Injection

The most frequent adverse reactions are underscored:

1. General: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of mouth, nose, and throat.

2. Cardiovascular System: Hypotension, headache, palpitations, tachycardia, extrasystoles.

3. Hematologic System: Hemolytic anemia, thrombocytopenia, agranulocytosis.

4. Nervous System: Sedation, sleepiness, dizziness, disturbed coordination, fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, neuritis, convulsions.

5. GI System: Epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation.

6. GU System: Urinary frequency, difficult urination, urinary retention, early menses.

7. Respiratory System: Thickening of bronchial secretions, tightness of chest or throat and wheezing, nasal stuffiness.

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Diphenhydramine Injection USP

The most frequent adverse reactions are italicized.

General

Urticaria; drug rash; anaphylactic shock; photosensitivity; excessive perspiration; chills; dryness of mouth, nose and throat.

Cardiovascular System

Hypotension, headache, palpitations, tachycardia, extrasystoles.

Hematologic System

Hemolytic anemia, thrombocytopenia, agranulocytosis.

Nervous System

Sedation, sleepiness, dizziness, disturbed coordination, fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, neuritis, convulsions.

Gastrointestinal System

Epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation.

Genitourinary System

Urinary frequency, difficult urination, urinary retention, early menses.

Respiratory System

Thickening of bronchial secretions, tightness of chest and wheezing, nasal stuffiness.

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Diphenhydramine Injection, USP

The most frequent adverse reactions are italicized.

General

Urticaria; drug rash; anaphylactic shock; photosensitivity; excessive perspiration; chills; dryness of mouth, nose and throat.

Cardiovascular System

Hypotension, headache, palpitations, tachycardia, extrasystoles.

Hematologic System

Hemolytic anemia, thrombocytopenia, agranulocytosis.

Nervous System

Sedation, sleepiness, dizziness, disturbed coordination, fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, neuritis, convulsions.

Gastrointestinal System

Epigastric distress, anorexia, nausea, vomiting, diarrhea, constipation.

Genitourinary System

Urinary frequency, difficult urination, urinary retention, early menses.

Respiratory System

Thickening of bronchial secretions, tightness of chest and wheezing, nasal stuffiness.

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