Who should not take Synthroid
A contraindication is a condition under which Synthroid (Levothyroxine) should not be taken because the risk outweighs the benefit. Synthroid has both absolute contraindications (do not use) and relative cautions (use only after careful review). This page summarises both at the 25mcg, 50mcg, 75mcg, 100mcg, 150mcg dosing range.
Absolute contraindications
According to the prescribing information for Levothyroxine, absolute contraindications typically include severe allergic reactions to the active ingredient or excipients, severe hepatic or renal impairment, certain cardiovascular conditions, and concurrent use of specific interacting medications. The exact list depends on the molecule and is detailed in the official label.
Relative cautions
Relative cautions are situations where Synthroid can be used but with extra monitoring, dose reduction or alternative considered. These often include mild-to-moderate organ impairment, age extremes, multiple comorbidities, and complex medication regimens. Levothyroxine replaces deficient endogenous thyroxine, which is converted in tissues to the active hormone triiodothyronine (T3) by deiodinase enzymes.
Frequently asked questions
Can someone with heart disease take Synthroid? ▾
Some forms of heart disease are absolute contraindications for Synthroid, particularly with nitrate use or recent cardiovascular events. Stable, well-controlled cardiovascular disease may allow Synthroid use under specialist supervision. The prescribing information for Levothyroxine should be reviewed.
Is Synthroid safe with kidney problems? ▾
Mild to moderate kidney impairment usually allows Synthroid at adjusted lower 25mcg, 50mcg, 75mcg, 100mcg, 150mcg doses. Severe kidney failure is often a contraindication or requires substantial dose reduction. The prescriber decides based on lab results and concurrent medications.
More on Synthroid
- With alcoholSynthroid and alcohol — is it safe to drink?
- With foodShould Synthroid be taken with food?
- Side effectsSynthroid side effects: common, rare and warning signs
- Dosage guideSynthroid dosage guide: how much to take and when
- OnsetHow fast does Synthroid start working?
- DurationHow long does Synthroid last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.