Atropine

Major Uses

Atropine can be used in many different situations and is safe enough to give to most species. Primarily, it is administered prior to anesthesia for surgery to prevent or reduce drooling, respiratory tract secretions, or gastrointestinal secretions. The drug can increase heart rate, and it has shown to play an important role in CPR when a patient's heart rate is slowing. Atropine can be used as an antidote for insecticide, mushroom, and algae poisoning. The drug also dilates pupils to reduce eye pain and dilates airways in animals that have difficulty breathing.

Common Precautions

Typically known to be a safe drug, atropine has very little side effects when normal doses are given to relatively healthy patients. Most adverse effects occur at high doses. These effects may include dry mouth, dysphagia (difficulty swallowing), increase in thirst, constipation, vomiting, and urine retention. Blurred vision, drowsiness, ataxia (uncoordinated movements), seizures, and respiratory depression are also seen in some patients. Cardiovascular effects that have been reported with the use of atropine are increased heart rate at high doses, decreased heart rate at low doses, irregular heartbeats, and circulatory failure.

Atropine should not be administered to patients with glaucoma or those with adhesions between the iris and lens of the eye. The drug should be used with extreme caution in animals with rapid heart rates, bowel obstructions or inflammation, certain cardiovascular issues, impaired kidney or liver function, and those that have signs of gastrointestinal infections or diseases. There may be some risk with the use of atropine in pregnant or lactating animals as well. The pet's veterinarian should be informed of other medications the pet is currently taking, as atropine can interact with other substances. Some examples of other medications prone to an interaction include antihistamines, diazepam, and metoclopramide.

Atropine should not be administered to animals with a known allergy or hypersensitivity to the drug or other anticholinergic drugs. The prescribing veterinarian should be contacted if any questionable symptoms occur.

Storage

Atropine tablets should be stored in tight, childproof containers at room temperature. The injectable form should also be kept at room temperature, and proper care should be taken so it is kept from freezing.

Administration

Atropine is available in injectable and tablet form, as well as an ophthalmic solution. The typical dosage for atropine when used as a preanesthetic adjuvant is 0.01 - 0.02 mg/lb (0.022-0.044 mg/kg), and as an antidote for poisonings, high doses, up to 1 mg/lb (2 mg/kg) may be necessary. For the ophthalmic solution, one drop every 2-24 hours is what may be prescribed. Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.