Paremyd (Hydroxyamphetamine and tropicamide) - Uses, Dose, MOA

Hydroxyamphetamine and tropicamide are two different drugs used in ophthalmology for diagnostic and therapeutic purposes.

  • Hydroxyamphetamine:
    • Function: Hydroxyamphetamine is primarily used in ophthalmic diagnostic procedures to help differentiate between pre- and postganglionic nerve lesions in the sympathetic nervous system. It is part of a test known as the hydroxyamphetamine test.
    • Hydroxyamphetamine Test: This test involves the administration of hydroxyamphetamine eye drops. If the pupil dilates after the administration of hydroxyamphetamine, it suggests that the defect is postganglionic (beyond the ciliary ganglion). If there is no dilation, it indicates a preganglionic defect (before the ciliary ganglion).
  • Tropicamide:
    • Function: Tropicamide is a muscarinic receptor antagonist and is used as a mydriatic (pupil-dilating) agent. It is commonly used in eye examinations to dilate the pupil for various diagnostic procedures, such as fundoscopy or refraction assessments.
    • Mydriasis: Tropicamide works by blocking the action of acetylcholine in the eye, leading to dilation of the pupil (mydriasis) and paralysis of the ciliary muscle, which helps in examining the retina and determining the refractive errors of the eye.

These drugs are often used in combination or in sequence during eye examinations to obtain a comprehensive assessment of the patient's ocular health.

Paremyd (Hydroxyamphetamine and tropicamide) is a combination of sympathetic nervous system activating drug and parasympatholytic drug. It is used to dilate the pupils as in certain diagnostic procedures.

Hydroxyamphetamine and tropicamide Uses:

  • Mydriasis:
    • It is used for the short-term pupillary dilation as in diagnostic procedures.

Hydroxyamphetamine and tropicamide (Paremyd) Dose in Adults

Hydroxyamphetamine and tropicamide (Paremyd) Dose in the treatment of Mydriasis:

  • The usual method is to put 1 to 2 drops in the space between the eyeball and the eyelid (conjunctival sac).
  • This helps eye doctors examine the eyes more thoroughly.

Use in Children:

Not indicated.

Pregnancy Risk Factor C

  • There haven't been studies done on how this combination of drugs affects animals during pregnancy.
  • If someone needs to use eye medications while pregnant, it's suggested to use the smallest effective amount.
  • This is done along with blocking the tear ducts to lower the chance of the baby being exposed to the medication. This information is based on a study from 1988.

Use of tropicamide and hydroxyamphetamine during breastfeeding:

  • We don't know if hydroxyamphetamine or tropicamide, the drugs in question, pass into breast milk.
  • The company that makes these drugs suggests being careful when giving them to breastfeeding mothers.

Dose in Kidney Disease:

  • The instructions from the manufacturer don't specify any changes in the dosage of these drugs for people with kidney problems.

Dose in Liver disease:

  • The instructions from the manufacturer don't mention any changes in the dosage of these drugs for people with liver issues.

Side effects of Hydroxyamphetamine and tropicamide (Paremyd):

It is Reported with Paremyd or similar medications.

  • Cardiovascular:
    • Hypotension
    • Ventricular Fibrillation
    • Myocardial Infarction
    • Tachycardia
  • Dermatologic:
    • Pallor
  • Central Nervous System:
    • Headache
    • Behavioral Problems
    • Psychosis
  • Hypersensitivity:
    • Hypersensitivity Reaction
  • Gastrointestinal:
    • Nausea
    • Vomiting
    • Xerostomia
  • Neuromuscular & Skeletal:
    • Muscle Rigidity
  • Ophthalmic:
    • Blurred Vision
    • Stinging Of Eyes (Transient)
    • Increased Intraocular Pressure
    • Photophobia

Contraindications to Hydroxyamphetamine and tropicamide (Paremyd):

  • If someone is allergic to hydroxyamphetamine, tropicamide, or any part of the medication, or if they have a specific type of glaucoma (angle-closure glaucoma) or narrow angles in their eyes, they shouldn't use these drugs because it could worsen their eye condition.

Warnings and precautions

CNS effects

  • These medications may make you feel sleepy or cause your vision to be blurry.
  • This could affect your ability to do things that need you to be alert, like driving or using machinery.

Increased intraocular pressure

  • These medications might cause a temporary rise in eye pressure.
  • If you have glaucoma, you should be careful when using them.

Cardiovascular disease

  • If you have heart-related issues like high blood pressure, irregular heartbeats, or problems with blood flow to the heart, be cautious when using these medications.
  • Your doctor should keep an eye on your condition after you use them.


  • If you have diabetes, be careful when using these medications.
  • Your doctor should keep an eye on your condition after you use them.

Thyroid disease:

  • If you have an overactive thyroid (hyperthyroidism), be cautious when using these medications.
  • Your doctor should keep an eye on your condition after using them.

Monitoring parameters:

Ophthalmic Exam:

  • These medications are used for eye examinations.
  • They help eye doctors see the inside of the eye more clearly.

Intraocular Pressure:

  • There might be a temporary increase in eye pressure.
  • If you have glaucoma, be cautious when using these medications.

CNS Reactions (Especially in Pediatric Patients):

  • May cause drowsiness and/or blurred vision.
  • Be cautious with activities requiring mental alertness, like driving or using machinery.
  • Extra care is needed, especially in children, to monitor and manage any central nervous system effects.

How to administer Hydroxyamphetamine and tropicamide (Paremyd)?

For Topical Ophthalmic Use Only:

  • These eye drops are meant for use on the eyes only.

To Avoid Excessive Systemic Absorption:

  • After applying the drops, gently press on the inner corner of the eye near the nose for 2 to 3 minutes.
  • This helps prevent too much of the medication from getting into the bloodstream.

Do Not Touch Dropper Tip to Eyelids or Other Surfaces:

  • When putting in the drops, avoid touching the dropper tip to your eyelids or any other surfaces.
  • This helps prevent contamination.

Wash Hands Following Administration:

  • After using the eye drops, be sure to wash your hands thoroughly.
  • This helps avoid spreading any residue and keeps things clean.

Mechanism of action of Hydroxyamphetamine and tropicamide:

Hydroxyamphetamine Hydrobromide:

  • Type: Indirect acting sympathomimetic agent.
  • Action: Causes the release of norepinephrine from adrenergic nerve terminals.
  • Result: Leads to mydriasis (pupil dilation).


  • Type: Parasympatholytic agent.
  • Action: Blocks the sphincter muscle in the iris and the ciliary muscle.
  • Result: Produces mydriasis and paralysis, leading to pupil dilation.

Onset of Action:

  • Time: 15 minutes
  • Meaning: The effects of the medication typically begin about 15 minutes after it is administered.


  • Time: 3 hours
  • Complete Recovery: Usually occurs in 6-8 hours, but it might take up to 24 hours for all effects to wear off.

Time to Peak:

  • Time: 60 minutes
  • Meaning: The medication reaches its maximum effectiveness around 60 minutes after administration.

International Brand Names of Hydroxyamphetamine and tropicamide:

  • Paremyd

Hydroxyamphetamine and tropicamide Brand Names in Pakistan:

Not available.