Credits

• Section Writer: Dr. Om J Lakhani
• Section Editor: Dr. Om J Lakhani

Q. Enlist the complications of Thionamides (Anti-thyroid drugs) ?

• Common
  • Vomiting, nausea
  • Rash, urticaria
  • Arthritis, arthralgia
  • Fever
  • Abnormal taste sensation
• Agranulocytosis
  • 0.1-0.5 % risk
  • Get CBC done at the start of therapy
  • Repeat CBC if c/o of fever, sore throat, etc
• Liver disease
  • Methimazole, Carbimazole- cholestatic hepatitis
  • PTU – idiosyncratic liver failure
• others
  • Teratogenicity -With methimazole
  • ANCA positive vasculitis – with PTU > Methimazole
  • Insulin autoimmune Syndrome (Hirata syndrome)- Methimazole
  • Pancreatitis- rarely with methimazole

Q. What are the advantages of methimazole over PTU?

• Longer half-life of 4-6 hours compared to 75 min of PTU
• More intrathyroidal concentration
• Superior blockage of TPO as evidence by perchlorate discharge test
• PTU has a risk of idiosyncratic liver toxicity
• PTU has more radioiodine failure

Q. In which cases is PTU preferred over methimazole?

• Pregnancy 1st trimester
• Thyroid storm
• Reaction of Methimazole (other than agranulocytosis) and not candidates for radioactive iodine

Q. What is Neutropenia?

• Neutropenia refers to a decrease in circulating neutrophils, which for adults corresponds to <1500 cells/microL in most clinical laboratories.

Q. What is the normal neutrophil count?

• Normal neurotrophil in adults is 4400 to 11,000 cells/microL

Q. What is the absolute neutrophil count?

• Absolute neutrophil count – The absolute neutrophil count (ANC) is the number of neutrophils plus bands but does not include metamyelocytes and less mature forms.
• ANC = WBC (cells/microL) x percent (PMNs  +  bands) ÷ 100

Q. Please give the category of neutropenia

• Neutropenia can be categorized as:
  • Mild – ANC ≥1000 and <1500 cells/microL
  • Moderate – ANC ≥500 and <1000 cells/microL
  • Severe – ANC <500 cells/microL
  • Agranulocytosis – ANC <200 cells/microL