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Levothyroxine

Brand: Synthroid, Levoxyl

Thyroid hormoneUsed for: Hypothyroidism (underactive thyroid)Endocrine & Diabetes
Key warning

Boxed warning: not for obesity or weight loss; large doses can cause serious or fatal toxicity

Common side effects

  • Rapid heartbeat
  • Nervousness
  • Insomnia
  • Weight loss
  • Tremor

Key interactions & cautions

  • Separate from calcium and iron by 4 hours
  • Antacids reduce absorption
  • Take away from certain foods and fiber
  • Affects warfarin blood thinner

Counseling points

  • Take on an empty stomach in the morning
  • Wait 30-60 minutes before eating
  • Take at the same time each day
  • Do not switch brands without approval
  • Report chest pain or palpitations

High-yield study aid for exam prep — not a substitute for the package insert or a pharmacist’s dispensing reference.