Tropicamide: Components, Presentation, Indications, Mechanism of Action, Dosage and Side Effects

The objective of this drug is to produce a dilation in the pupil or a momentary paralysis, and it is used in ocular explorations.

Tropicamide, an anticholinergic administered generally under medical prescription, is presented in the form of ophthalmological drops that block the responses of the sphincter muscle of the iris .

Causing a dilation of the pupil or a mydriasis , as well as momentary paralysis of the ciliary muscle to make it impossible to accommodate the lens, known as cycloplegia.

Components

  • Benzalkonium Chloride, Sodium Edetate 2H2O, Polysorbate 80, Sodium Metabisulfite and Sodium Chloride.

Presentation

  • Ophthalmic solution, each ml contains 10 mg of tropicamide.

Indications

Due to its ability to dilate the pupil while maintaining its effects, this eye drop is usually used by specialists, temporarily and controlled, in order to:

  • Thoroughly explore the interior of the eye, which is called the fundus, by dilating the pupil and blocking the sphincter muscle of the iris and the muscle of the ciliary body.
  • In some surgical interventions where it is required that the pupil is dilated.
  • It is sometimes used as a rapid-acting mydriatic in some pre and post-operative periods.

Mechanism of action

Tropicamide is an anticholinergic eye drop that works by blocking the responses of the sphincter muscle of the iris and the ciliary body muscle to stimulation caused by acetylcholine.

The solution used with a concentration of 0.5% produces dilatation of the pupil and the concentration of the solution at 1% produces paralysis of the accommodation.

Dose

The tropicamide is not a medicine of daily use, as if it is the artificial tears or the refreshing eye drops, this is a medicine that should only be recommended and administered by a doctor.

Within the conditions for its correct administration the following ones can be enunciated:

  • It should only be used in those circumstances where the pupil must be dilated, usually to perform eye examinations such as the fundus or in some eye surgeries.
  • The application should be made 15 to 20 minutes before the intervention.
  • The application must be carried out by a specialized staff at all times.
  • In the examinations where the refraction is carried out, the recommended dose is one drop of ophthalmic solution at 1% and another drop is added five minutes later.
  • The intervention of the specialist must be done in 20 or 30 minutes after giving the drops to the patient. If for any reason, the assessment lasts more than 30 minutes between the time of administration of the drops and the assessment made by the specialist, it is recommended to place an additional third drop.
  • In children the concentration of eye drops is usually reduced from 1 to 0.5%.

Side effects

Tropicamide usually causes an increase in intraocular pressure, very slightly.

It can also cause redness of the eye, conjunctivitis , glare, photophobia, palpebral edema and variations in the patient’s visual capacity during the duration of the effect of its administration.

So you should be careful not to drive vehicles, until you recover your normal visual capacity.

When the recommended doses are applied, the adverse effects are only local.

Only in exceptional cases can systemic anticholinergic effects occur.

It is very rare occurrence that at the level of the central nervous system , symptoms such as somnolence, sedation, alteration of behavior, psychosis, headaches, hallucinations (usually in children) occur.

At the cardiovascular level, it rarely causes tachycardia.

In the gastrointestinal tract, dry mouth.

And in the skin, exanthematic eruptions of rare occurrence.

Warnings and contraindications

This is a drug that requires a prescription for its acquisition and should be used with extreme caution:

During pregnancy: Women in pregnancy should restrict their use, as there are reports that there is a certain risk of causing damage to the fetus.

During breast-feeding: Breast-feeding is not recommended during treatment, as it is not known if it is excreted in breast milk.

Glaucoma : Its use is not recommended in patients diagnosed with glaucoma, as is the case of narrow-angle glaucoma.

Irritation: If the patient has swollen eyes, it is recommended to defer the test until inflammation has subsided, since this medication can aggravate these symptoms.

Ability to drive: After administration, symptoms such as blurred vision and other visual disturbances may appear for a long time.

Normally within a few hours of its application, the effects of this eye drop disappear completely and the patient returns to normal, but in some cases it may last a little longer.

These effects affect the ability to use machinery or drive. You must not drive or use machines until you are in the optimal state to do so.

Limited use: Extreme caution must be exercised in its use, so only in cases where it is necessary to use it.