I prepared these slides for my pharmacology class with Pharmacology and the Nursing Process by Lilley as my main reference. I managed to pick out a lot of the most important points for your studying pleasure.

1. ANTITHYROID DRUGS
Used mainly for the treatment of HYPERTHYROIDISM
Hyperthyroidism is characterized by over secretion of thyroid hormone.
In severe cases, it is called thyrotoxicosis.

2. Hyperthyroidism Treatment is aimed at:
• Primary cause of Disease
• Symptoms of the Disease
Some drugs used to treat causes are:
• Antithyroid Drugs
• Iodides
• Radiactive isotopes of Iodine (Iodine 131-destroys thyroid tissue by ablation).
• Ionic inhibitors
• Surgery
Drug for symptoms: Beta Blockers

3. Causes:
• Graves’ disease (autoimmune
disease); most common cause
• Plummer’s disease
• Multi-nodular disease
• Thyroid storm
Symptoms:
• Diarrhea
• Flushing
• Increased appetite
• Muscle weakness
• Fatigue
• Palpitations
• Irritability
• Nervousness
• Sleep disorders
• Heart Intolerance
• Altered menstrual flow

4. Main Drugs: Thioamide derivatives
•Drug of choice: PROPYLTHIOURACIL
•Methiomazole

5. Mechanism of Action
Inhibit incorporation of iodine molecules into amino
acid Tyrosine.
Diiodotyrosine (main constituent of thyroid
hormones) is not formed.
Thyroxine (T4) and Triodothyroxine (T3)
production is impeded.
PTU can inhibit conversion of T4 to T3 in peripheral
circulation
*No drug inactivates existing thyroid hormone.

6. Effects
• Primarily limited to Thyroid Gland
• Overall decrease in Thyroid hormone level in circulation
• Normalizes overall metabolic rate in patients with hyperthyroidism

7. Indications
• Hyperthyroidism
• Hormonal surge after thyroidectomy
• Grave’s disease (usually for several years)

8. Contraindications
• Known drug allergy
• Controversial in pregnancy; linked to scalp abnormalities
oPTU may be used in 1st trimester only.
oMethimazole may be used in 2nd and 3rd trimesters only
Adverse Effects
• Liver and Bone Marrow toxicity
Interactions
• Bone marrow depressants (additive effects)
• Oral anticoagulants (risk for bleeding)

9. Dosages

10. Assessment
• Vital Signs
• Signs of Thyroid crisis
• Causes of stress or infection

11. Implementation
• Dose with meals to prevent stomach upset
• Report fevers, sore throat, mouth ulcers, unusual bleeding or burning
which may indicate liver and bone marrow toxicity
• Avoid iodized salt, shellfish, tofu, eggs, soy products etc
• Educate patient about signs of hypothyroidism
• Monitor blood count for leukopenia (death of WBCs)