Difenidol: Uses, Action Mechanism, Use Mode, Side Effects, Precautions and Interactions

It is a drug that works as a muscarinic antagonist.

Uses of Diphenidol

This medication is for the prevention and symptomatic treatment of dizziness and nausea, vomiting, peripheral vertigo (labyrinth), and symptoms in conditions such as Meniere’s disease and in-ear surgery and ear disorders.

Suppressive medications and vestibular antiemetics are the basis of the treatment of vertigo. The term “vestibular suppressor” is a vague term generally used to indicate drugs that reduce nystagmus caused by a vestibular imbalance or that reduce motion sickness.

However, if you already have nausea and vomiting, it is best to keep the stomach empty, and this medication should be taken with only a tiny amount of water. Take this medication only as directed.

Diphenidol has been used to treat ventricular tachyarrhythmias; however, the use of Diphenidol as an antiarrhythmic is not justified due to the frequency and severity of the adverse effects on the central nervous system (CNS).

Diphenidol is not indicated for use in nausea and vomiting of pregnancy.

Studies in humans and animals have not shown a significant difference in conception rate, several births, birth or viability, or birth abnormalities between control groups treated with Difenidol and those not treated.


Mechanism of action

It belongs to the compounds that contain a diphenylmethane residue, which consists of methane in which two hydrogen atoms are replaced by two phenyl groups.

The mechanism by which Difenidol exerts its effects is not known with precision. It is thought to decrease vestibular stimulation and depress labyrinthine function as an antimuscarinic agent.

A non-selective Mach receptor antagonist and non-specific inhibitor of ion-dependent voltage channels in neurons; used to study animal models of vertigo and emesis.

Diphenidol is a non-selective muscarinic acetylcholine receptor antagonist. It is also a non-specific inhibitor of voltage-dependent ion channels (Na +, K +, and Ca2 +) in neurons.

Diphenidol has been used to inhibit the triggering induced by rotation of neurons of the medial vestibular nucleus type 1 in a model of vertigo in cats and to block the activation zone of the chemoreceptor in the medulla that controls the vomiting induced by apomorphine in a model of emesis in dogs.

Before using Diphenidol

Difenidol should not be administered to pregnant mothers or patients suffering from kidney dysfunction.

If the prescribing authority justifies the benefits of the medication against possible harm, it must re-evaluate them and consult the reference material and previous studies.

For this medication, the following should be considered:

Patient allergies:

Tell your doctor if you have ever had any unusual or allergic reaction to Diphenidol or other medicines. Also, report all your allergies, such as food, dyes, preservatives, or animals. For non-prescription products, carefully read the label or ingredients of the package.

Other interactions:

Certain medications should not be used at or near eating since certain foods are eaten as interactions may occur.

Other medical problems:

The presence of other health problems may affect the use of Diphenidol. Be sure to inform your doctor, especially if you have:

  • Enlarged prostate.
  • Glaucoma.
  • Bowel block
  • Low blood pressure .
  • A stomach ulcer (Difenidol can make conditions worse).
  • Kidney diseases
  • Blockage of the urinary tract, there may be higher levels of Diphenidol in the blood, which increases the chances of side effects.

How to use

Take this medication orally exactly as prescribed. Do not increase the dose without consulting your doctor. Your condition will not get better faster, but it can increase the risk of side effects.

Side effects

Headache, upset stomach, dry mouth, blurred vision, sleep disturbances, and drowsiness may occur during the first few days as your body adjusts to the medication. If any of these effects continue or become bothersome, inform your doctor.

Check with your doctor if you experience any of the following side effects:

Uncommon symptoms:

  • Confusion.
  • Hallucinations (see, hear or feel things that are not there).

Symptoms of overdose:

  • Drowsiness (severe)
  • Difficulty breathing or breathing problems.
  • Severe tiredness or unusual weakness

Some side effects do not require medical attention.

Check with your doctor if the following side effects continue:

  • Blurry vision.
  • Dizziness.
  • Dry mouth.
  • Headache.
  • Acidity.
  • Nervousness, restlessness, or trouble sleeping.
  • Acne.
  • Stomach upset or pain
  • Unusual tiredness or weakness

If you notice any other symptoms or effects, check with your doctor.

Tell your doctor if you have: hallucinations, confusion, disorientation, depression, rash, and increased stimulation. Be careful when operating machinery or participating in activities that require alertness.


Tell your doctor about your medical history, especially kidney disease, ulcers, stomach or bowel disorders, prostate problems, glaucoma, heart disease, or allergies.

Diphenidol should be used only if needed during pregnancy. Discuss with your doctor. It is not known if this medication appears in breast milk.

This medication will increase the effects of alcohol and other central nervous system depressants (medicines that make you sleepy or less alert).

Some central nervous system depressants are antihistamines or medications for hay fever, other allergies, or colds; sedatives, tranquilizers, sleeping medications; medication prescribed for pain or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics.

Check with your doctor before taking any of the above drugs while using this medicine.

Be sure you know how you react to Difenidol before driving, using machines, or doing anything else that may be dangerous if you are dizzy, not attentive, or do not have a clear vision.

Drug interactions

Tell your doctor any over-the-counter or prescription medications you can take. Limit alcohol consumption while taking this medication. Do not start or stop any medicine without the approval of a doctor or pharmacist.


The dose of Difenidol is different for all patients. This information refers only to the average amounts of Difenidol. If your dose is extra, do not change it unless your doctor orders it.

The amount of Diphenidol assigned to you depends on the potency of the medication.

For the oral dose of pills or tablets:

  • An Adultos: from 25 to 50 milligrams (mg) every 4 hours as necessary.
  • Children: the amount is based on weight and must be set by a doctor.
  • Neonatal (3kg): there is no data available regarding the neonatal dosing details of Difenidol.

Try to take each dose at the scheduled time. If you miss a dose, take it as soon as you remember, do not take it if it is almost time for the next dose; instead, skip the missed dose and resume your usual dosing schedule.

If an overdose of Diphenidol is suspected, call immediately for emergencies.


  • Store Diphenidol at room temperature between 59 and 86 degrees F (15 and 30 degrees C) away from heat and light.
  • Do not store it in the bathroom.

Alternative Names of Difenidol

Generic names:

  • Difenidol, Difenidol HCl, Difenidol Hydrochlorurous, Diphenidol, Diphenidol.


  • Ansmin, Avomol, Celmidol, Cephadol, Cerrosa, Maniol, Nometic, Satanolon, Verterge, Vontrol, Yesdol.