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Histex PD Drops

Generic Name: triprolidine (trye PROE li deen)
Brand Name: Histex PD Drops, Histex Syrup, M-Hist PD, Vanaclear PD, Vanahist PD, Zymine

Medically reviewed on April 19, 2017

What is Histex PD Drops?

Histex PD Drops is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

Histex PD Drops is used to treat sneezing, runny nose, watery eyes, hives, skin rash, itching, and other cold or allergy symptoms.

Histex PD Drops may also be used for purposes not listed in this medication guide.

Important Information

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

You should not use antihistamine medication to make a child sleepy.

Before taking this medicine

You should not use Histex PD Drops if you are allergic to it.

Ask a doctor or pharmacist if it is safe for you to use this medicine if you have other medical conditions, especially:

It is not known whether Histex PD Drops will harm an unborn baby. Ask a doctor before using this medicine if you are pregnant.

It is not known whether Histex PD Drops passes into breast milk or if it could affect a nursing baby. Antihistamines can slow breast milk production. Ask a doctor before using this medicine if you are breast-feeding.

Artificially sweetened liquid medicine may contain phenylalanine. Check the medication label if you have phenylketonuria (PKU).

How should I take Histex PD Drops?

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended. Cough or cold medicine is usually taken only for a short time until your symptoms clear up.

Do not give this medicine to a child younger than 4 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

You should not use antihistamine medication to make a child sleepy.

Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Do not take for longer than 7 days in a row. Call your doctor if your symptoms do not improve after 7 days of treatment, or if you have a fever with a headache, cough, or skin rash.

If you need surgery, tell the surgeon ahead of time that you are using Histex PD Drops. You may need to stop using the medicine for a short time.

Store at room temperature away from moisture and heat. Do not allow the liquid form of this medicine to freeze.

What happens if I miss a dose?

Since Histex PD Drops is used when needed, you may not be on a dosing schedule. If you are on a schedule, use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Histex PD Drops?

This medicine may cause blurred vision or impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.

Drinking alcohol can increase certain side effects of Histex PD Drops.

Ask a doctor or pharmacist before using any other cold, cough, allergy, or sleep medicine. Many combination medicines contain antihistamines. Taking certain products together can cause you to get too much of this type of medicine.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Histex PD Drops can decrease sweating and you may be more prone to heat stroke.

Histex PD Drops side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using Histex PD Drops and call your doctor at once if you have:

  • painful or difficult urination.

Common side effects may include:

  • headache, dizziness, drowsiness;

  • blurred vision;

  • dry mouth, nose, or throat;

  • nausea, vomiting, loss of appetite, constipation;

  • increased urination; or

  • feeling nervous or restless (especially in children).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect Histex PD Drops?

Ask a doctor or pharmacist before using this medicine if you are also using any other drugs, including prescription and over-the-counter medicines, vitamins, and herbal products. Some medicines can cause unwanted or dangerous effects when used together. Not all possible interactions are listed in this medication guide.

Taking this medicine with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking Histex PD Drops with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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

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