Tony Stark
January 13, 2025
3

Coreg and Synthroid Interactions Checker

Postural hypotension occurred in 1.8% and syncope in 0.1% of hypertensive subjects, primarily following the initial dose or at the time of dose increase and was a cause for discontinuation of therapy in 1% of subjects. Subjects treated with carvedilol showed significant improvements in global assessments compared with those treated with placebo in COPERNICUS. In the rats, there was also a decrease in fetal body weight at 300 mg per kg per day (50 times the MRHD as mg per m²) accompanied by an increased incidence of fetuses with delayed skeletal development. In rats, the no-effect level for embryo-fetal toxicity was 60 mg per kg per day (10 times the MRHD as mg per m²); in rabbits, it was 15 mg per kg per day (5 times the MRHD as mg per m²). The no-effect level was 12 mg per kg per day (2 times the MRHD as mg per m²). The timing of meals relative to your oral levothyroxine dose can affect the absorption of the medication.

If tolerated, patients may have their dose increased to 6.25, 12.5, and 25 mg twice daily over successive intervals of at least 2 weeks. A maximum dose of 50 mg twice daily has been administered to patients with mild-to-moderate heart failure weighing over 85 kg (187 lbs.). Retrospective analysis of side effects in clinical trials showed that poor 2D6 metabolizers had a higher rate of dizziness during up-titration, presumably resulting from vasodilating effects of the higher concentrations of the α-blocking R(+) enantiomer. Table 2 shows adverse events in U.S. placebo‑controlled clinical trials for hypertension that occurred with an incidence of greater than or equal to 1% regardless of causality and that were more frequent in drug‑treated subjects than placebo‑treated subjects.

The risk for these events was highest during the first 30 days of dosing, corresponding to the up-titration period and was a cause for discontinuation of therapy in 0.7% of subjects receiving COREG, compared with 0.4% of placebo subjects.
There was at least a trend toward improvement in NYHA class in a l trials.
Pregnant women with hypertension should be carefully monitored and managed accordingly.
Concomitant administration with a diuretic can be expected to produce additive effects and exaggerate the orthostatic component of carvedilol action.

Drug-Drug Interactions

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What happens if I miss a dose?

You should separate the administration of levothyroxine and multivitamin with minerals by at least 4 hours. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. Common side effects of Coreg include low blood pressure, weight gain, and fatigue.

Drug Summary

All randomized subjects had tolerated a 2‑week course on carvedilol 6.25 mg twice daily. Of the 765 subjects with heart failure randomized to COREG in U.S. clinical trials, 31% (235) were aged 65 years or older, and 7.3% (56) were aged 75 years or older. Of the 1,156 subjects randomized to COREG in a long‑term, placebo‑controlled trial in severe heart failure, 47% (547) were aged 65 years or older, and 15% (174) were aged 75 years or older. Of 3,025 subjects receiving COREG in heart failure synthroid fainting trials worldwide, 42% were aged 65 years or older. Amiodarone and its metabolite desethyl amiodarone, inhibitors of CYP2C9, and P- glycoprotein increased concentrations of the S(-)-enantiomer of carvedilol by at least 2 fold see Clinical Pharmacology (12.5). The concomitant administration of amiodarone or other CYP2C9 inhibitors such as fluconazole with COREG may enhance the β-blocking activity resulting in further slowing of the heart rate or cardiac conduction.

Drug Interaction Classification

Changes in excretion of sodium, potassium, uric acid, and phosphorus in hypertensive patients with normal renal function were similar after COREG and placebo. The basis for the beneficial effects of COREG in patients with left ventricular dysfunction following an acute myocardial infarction is not established. Cases of overdosage with COREG alone or in combination with other drugs have been reported. Of the 2,065 hypertensive subjects in U.S. clinical trials of efficacy or safety who were treated with COREG, 21% (436) were aged 65 years or older. Of 3,722 subjects receiving COREG in hypertension clinical trials conducted worldwide, 24% were aged 65 years or older. If such symptoms occur, diuretics should be increased and the carvedilol dose should not be advanced until clinical stability resumes see DOSAGE AND ADMINISTRATION.

CAPRICORN was a double-blind trial comparing carvedilol and placebo in 1,959 subjects with a recent myocardial infarction (within 21 days) and left ventricular ejection fraction of less than or equal to 40%, with (47%) or without symptoms of heart failure.
In a pharmacokinetic trial conducted in 8 healthy male subjects, rifampin (600 mg daily for 12 days) decreased the AUC and Cmax of carvedilol by about 70% see Drug Interactions (7.5).
Occasionally it is necessary to lower the carvedilol dose or temporarily discontinue it.
The dose-related blood pressure response was accompanied by a dose-related increase in adverse effects see ADVERSE REACTIONS.
The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for COREG and any potential adverse effects on the breastfed infant from COREG or from the underlying maternal condition.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. If treatment with COREG is to be continued perioperatively, particular care should be taken when anesthetic agents that depress myocardial function, such as ether, cyclopropane, and trichloroethylene, are used see Overdosage (10). The following adverse reactions have been identified during post-approval use of COREG. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. COREG should not be given to patients with severe hepatic impairment see Contraindications (4). Concomitant treatment included diuretics (99%), ACE inhibitors (91%), digitalis (59%), aldosterone antagonists (11%), and “statin” lipid-lowering agents (21%).

1 Heart Failure

It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor. If severe hypoglycemia occurs, patients should be instructed to seek emergency treatment. It is not known whether this formulation of metoprolol at any dose or this low dose of metoprolol in any formulation has any effect on survival or hospitalization in patients with heart failure. Thus, this trial extends the time over which carvedilol manifests benefits on survival in heart failure, but it is not evidence that carvedilol improves outcome over the formulation of metoprolol (TOPROL-XL) with benefits in heart failure.

All protocols excluded subjects expected to undergo cardiac transplantation during the 7.5 to 15 months of double-blind follow-up.
In each trial, there was a primary end point, either progression of heart failure (1 U.S. trial) or exercise tolerance (2 U.S. trials meeting enrollment goals and the Australia-New Zealand trial).
The primary P450 enzymes responsible for the metabolism of both R(+) and S(-)- carvedilol in human liver microsomes were CYP2D6 and CYP2C9 and to a lesser extent YP3A4, 2C19, 1A2, and 2E1.
The dosing recommendations should be followed closely and the dose should be lowered if any evidence of bronchospasm is observed during up-titration.
Five categories – A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Coreg may have serious side effects that include hypotension, chest pain, irregular heartbeat, difficult breathing and swallowing, hives or rash, swelling, and fainting. Worsening heart failure or fluid retention may occur during up-titration of carvedilol. If such symptoms occur, diuretics should be increased and the carvedilol dose should not be advanced until clinical stability resumes see Dosage and Administration (2).

If your doctor decides that you should stop taking Coreg, your doctor may slowly lower your dose over a period of time before stopping it completely. Blood pressure is the force of blood in your blood vessels when your heart beats and when your heart rests. High blood pressure makes the heart work harder to pump blood through the body and causes damage to blood vessels. Coreg can help your blood vessels relax so your blood pressure is lower.