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Histex Syrup

Generic name: triprolidine

Brand names: Histex PD Drops, Histex Syrup, M-Hist PD, PediaClear PD, Histex, Vanaclear PD, Vanahist PD

Last updated November 2, 2026 0 views
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What is Histex Syrup?

Histex Syrup is an antihistamine used to relieve sneezing, a runny nose, an itchy nose and throat, and itchy or watery eyes due to allergies like hay fever.

Histex Syrup may also be used for other reasons not mentioned in this medication guide.

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How should I take Histex Syrup?

Use exactly as directed on the label, or as prescribed by your doctor. Cold or cough medicine is only for short-term use until your symptoms clear up.

Always follow directions on the medicine label about giving cough or cold medicine to a child. Do not use the medicine only to make a child sleepy. Death can occur from the misuse of cough or cold medicines in very young children.

You must chew the chewable tablet before you swallow it.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Call your doctor if your symptoms do not improve after 7 days, or if you have a fever, rash, or headaches.

If you need surgery or medical tests, tell the doctor ahead of time if you have taken this medicine within the past few days.

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

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Warnings

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

You should not use antihistamines to make a child sleepy.

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Before taking this medicine

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

Ask a doctor or pharmacist if Histex Syrup is safe to use if you have:

  • a breathing disorder such as chronic bronchitis or emphysema;
  • glaucoma; or
  • an enlarged prostate and urination problems.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

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

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Histex Syrup side effects

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

Histex Syrup can cause serious side effects. Stop using Histex Syrup and contact your doctor immediately if you experience:

  • painful or difficult urination.

Common side effects of Histex Syrup may include:

  • dizziness, drowsiness;
  • blurred vision;
  • dry mouth, nose, or throat;
  • constipation;
  • increased urination; or
  • feeling nervous or restless (especially in children).

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

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What happens if I miss a dose?

Since Histex Syrup is taken as needed, you might not have a regular dosing schedule. If you miss a dose and it's almost time for your next one, just skip the missed dose. Do not take two doses at the same time.

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What happens if I overdose?

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

  • Avoid driving or hazardous activity until you know how Histex Syrup will affect you. Your reactions could be impaired.
  • Drinking alcohol can increase certain side effects of triprolidine.
  • Ask a doctor or pharmacist before using other cough or cold medicines that may contain similar ingredients.
  • Avoid becoming overheated or dehydrated during exercise and in hot weather. Histex Syrup can decrease sweating and you may be more prone to heat stroke.

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What other drugs will affect Histex Syrup?

Avoid using this medicine with other drugs that cause drowsiness or slow your breathing (such as opioid medicine, a muscle relaxer, or medicine for anxiety or seizures).

Ask a doctor or pharmacist before using any other medication, including prescription and over-the-counter medicines, vitamins, and herbal products.

Not all possible drug interactions are listed in this medication guide.

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Common questions about Histex Syrup

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Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.