Canis ISSN: 2398-2942

Levothyroxine

Synonym(s): T4, L-thyroxine

Introduction

Name

  • Levothyroxine.

Class of drug

  • Synthetic hormone.

Description

Physical properties

  • Tablets.

Storage requirements

  • <25°C.
  • Away from direct sunlight.

Uses

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Indications

  • Used to treat hypothyroidism Hypothyroidism.
  • A synthetically-prepared hormone.

Administration

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Pharmocokinetics

Precautions

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Interactions

with other drugs



Catecholamines
  • Epinephrine Epinephrine , norepinephrine.
  • Effects are enhanced by thyroxine.
Sympathomimetics
  • Effects are enhanced by thyroxine.
Warfarin
  • Potentiate the anticoagulant effects of warfarin Warfarin by increasing the catabolism of vitamin K-dependent clotting factors.
Insulin
  • Diabetic patients may have altered insulin Insulin requirements - monitor carefully during the initiation of therapy.
Estrogens
  • May increase thyroid requirements by increasing TBg Estradiol.
Digoxin, digitoxinKetamine
  • Increased risk of tachycardia and hypertension Ketamine.

with diagnostic tests

  • Many drugs (in humans) may have effects on thyroid function tests including anabolic steroids, antithyroid drugs, barbiturates, corticosteroids, diazepam, fluorouracil, heparin, insulin, mitotane (op-DDD), nitroprusside, oestrogens, phenylbutazone, phenytoin, propranolol, salicylates and thiazides.

Adverse Reactions

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Other sources of information

  • Based onSmall Animal Formulary.Tennant, Bryn (1999) 3rd edn. Cheltenham: BSAVA.

ADDED