Cythioate

By | 2010-07-28

Chemistry

Cythioate is an oral organophosphate agent.

Storage – Stability – Compatibility

Unless otherwise noted by the manufacturer store products in tight, light resistant containers at room temperature.

Pharmacology

After being distributed into body fluids, cythioate is ingested by fleas, ticks and demodectic mites. It then inhibits acetylcholinesterase thereby interfering with neuromuscular transmission.

Uses – Indications

Cythioate is approved for use for flea control in dogs of all ages. It may also be useful in treating tick infestations and the control od demodectic mites.

Pharmacokinetics

No information located.

Contraindications – Precautions – Reproductive Safety

Cythioate is contraindicated in greyhounds (no information located on safety in other sight hound breeds). It is also contraindicated in sick, debilitated, stressed (recovering from surgery, etc.), anemic or pregnant animals.

Adverse Effects – Warnings

Cythioate is relatively safe and at recommended doses should be devoid of adverse effects in otherwise healthy dogs. At higher doses and in susceptible dogs, muscle tremors and hyperexcitability may be noted.

Repeated or prolonged dosing may lead to adverse effects. The manufacturer warns against using cythioate simultaneously with other drugs, insecticides, pesticides or chemicals having cholinesterase inhibiting activity and using within a few days before or after using any other cholinesterase inhibitor.

Overdosage – Acute Toxicity

If overdoses occur, vomiting, tremors, hyperexcitability, salivation and diarrhea may occur. The manufacturer recommends treating with atropine at 0.22 mg/kg IM at 15-30 minute intervals depending upon the severity of the symptoms. Use of succinylcholine, theophylline/aminophylline, reserpine, and respiratory depressant drugs (e.g., narcotics, phenothiazines) should be avoided in patients with organophosphate toxicity. If an ingestion occurs by a human, contact a poison control center, physician or hospital emergency room.

Drug Interactions

Acepromazine or other phenothiazines should not be given within one month of worming with an organophosphate agent as their effects may be potentiated. Because of its anticholinesterase activity, avoid the use of organophosphates with DMSO. Cythioate could theoretically enhance the toxic effects of levamisole. Pyrantel Pamoate (or tartrate) adverse effects could be intensified if used concomitantly with an organophosphate. Patients receiving organophosphate anthelmintics should not receive succinylcholine or other depolarizing muscle relaxants for at least 48 hours. Drugs such as morphine, neostigmine, physostigmine and pyridostigmine should be avoided when using organophosphates as they can inhibit cholinesterase.

Doses

Doses for dogs:

For flea control:

a) Tablets: one 30 mg tablet for each 20 lbs of body weight once every third day or twice a week.

Liquid: 1 ml (16 mg) PO for each 10 lbs of body weight once every third day or twice a week. Apply to food and mix thoroughly. The first week of therapy will kill 95% of fleas. Additional treatments for several weeks are necessary to remove fleas that re-infest dogs from the environment. (Package insert; Proban® — Miles)

Monitoring Parameters

1) Efficacy;

2) Adverse effects

Client Information

Keep out of reach of children. Be sure client understands dosing recommendations and the importance of not exceeding them.

Dosage Forms – Preparations – FDA Approval Status – Withholding Times

Veterinary-Approved Products:

Cythioate Tablets 30 mg, 90 mg Cythioate Oral Liquid 1.6% (w/w) (16 mg/ml) in 25 ml and 120 ml containers; Proban® (Bayer); (Rx)

Human-Approved Products:

None