Drug Interactions between ampicillin and Levothyrox
This report displays the potential drug interactions for the following 2 drugs:
- ampicillin
- Levothyrox (levothyroxine)
Interactions between your drugs
No interactions were found between ampicillin and Levothyrox. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.
ampicillin
A total of 53 drugs are known to interact with ampicillin.
- Ampicillin is in the drug class aminopenicillins.
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Ampicillin is used to treat the following conditions:
- Bacteremia
- Bacterial Endocarditis Prevention
- Bacterial Infection
- Bronchitis
- Endocarditis
- Gastroenteritis
- Intraabdominal Infection
- Kidney Infections
- Leptospirosis
- Meningitis
- Otitis Media
- Peritonitis
- Pharyngitis
- Pneumonia
- Prevention of Perinatal Group B Streptococcal Disease
- Septicemia
- Shigellosis
- Sinusitis
- Skin or Soft Tissue Infection
- Surgical Prophylaxis
- Typhoid Fever
- Upper Respiratory Tract Infection
- Urinary Tract Infection
Levothyrox
A total of 211 drugs are known to interact with Levothyrox.
- Levothyrox is in the drug class thyroid drugs.
- Levothyrox is used to treat the following conditions:
Drug and food interactions
ampicillin food
Applies to: ampicillin
ADJUST DOSING INTERVAL: Certain penicillins may exhibit reduced gastrointestinal absorption in the presence of food. The therapeutic effect of the antimicrobial may be reduced.
MANAGEMENT: The interacting penicillin should be administered one hour before or two hours after meals. Penicillin V and amoxicillin are not affected by food and may be given without regard to meals.
References
- Neu HC (1974) "Antimicrobial activity and human pharmacology of amoxicillin." J Infect Dis, 129, s123-31
- Welling PG, Huang H, Koch PA, Madsen PO (1977) "Bioavailability of ampicillin and amoxicillin in fasted and nonfasted subjects." J Pharm Sci, 66, p. 549-52
- McCarthy CG, Finland M (1960) "Absorption and excretion of four penicillins." N Engl J Med, 263, p. 315-26
- Cronk GA, Wheatley WB, Fellers GF, Albright H (1960) "The relationship of food intake to the absorption of potassium alpha-phenoxyethyl penicillin and potassium phenoxymethyl penicillin from the gastrointestinal tract." Am J Med Sci, 240, p. 219-25
- Klein JO, Sabath LD, Finland M (1963) "Laboratory studies on oxacillin. I: in vitro activity against staphylococci and some other bacterial pathogens. II: absorption and urinary excretion in normal young." Am J Med Sci, 245, p. 399-411
- Neuvonen PJ, Elonen E, Pentikainen PJ (1977) "Comparative effect of food on absorption of ampicillin and pivampicillin." J Int Med Res, 5, p. 71-6
levothyroxine food
Applies to: Levothyrox (levothyroxine)
ADJUST DOSING INTERVAL: Consumption of certain foods as well as the timing of meals relative to dosing may affect the oral absorption of T4 thyroid hormone (i.e., levothyroxine). T4 oral absorption is increased by fasting and decreased by foods such as soybean flour (e.g., infant formula), cotton seed meal, walnuts, dietary fiber, calcium, and calcium fortified juices. Grapefruit or grapefruit products may delay the absorption of T4 thyroid hormone and reduce its bioavailability. The mechanism of this interaction is not fully understood.
MANAGEMENT: Some manufacturers recommend administering oral T4 as a single daily dose, on an empty stomach, one-half to one hour before breakfast. In general, oral preparations containing T4 thyroid hormone should be administered on a consistent schedule with regard to time of day and relation to meals to avoid large fluctuations in serum levels. Foods that may affect T4 absorption should be avoided within several hours of dosing if possible. Consult local guidelines for the administration of T4 in patients receiving enteral feeding.
References
- (2002) "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical
- (2022) "Product Information. Armour Thyroid (thyroid desiccated)." Forest Pharmaceuticals
- Wohlt PD, Zheng L, Gunderson S, Balzar SA, Johnson BD, Fish JT (2009) "Recommendations for the use of medications with continuous enteral nutrition." Am J Health Syst Pharm, 66, p. 1438-67
levothyroxine food
Applies to: Levothyrox (levothyroxine)
ADJUST DOSING INTERVAL: Concurrent administration of calcium-containing products may decrease the oral bioavailability of levothyroxine by one-third in some patients. Pharmacologic effects of levothyroxine may be reduced. The exact mechanism of interaction is unknown but may involve nonspecific adsorption of levothyroxine to calcium at acidic pH levels, resulting in an insoluble complex that is poorly absorbed from the gastrointestinal tract. In one study, 20 patients with hypothyroidism who were taking a stable long-term regimen of levothyroxine demonstrated modest but significant decreases in mean free and total thyroxine (T4) levels as well as a corresponding increase in mean thyrotropin (thyroid-stimulating hormone, or TSH) level following the addition of calcium carbonate (1200 mg/day of elemental calcium) for 3 months. Four patients had serum TSH levels that were higher than the normal range. Both T4 and TSH levels returned to near-baseline 2 months after discontinuation of calcium, which further supported the likelihood of an interaction. In addition, there have been case reports suggesting decreased efficacy of levothyroxine during calcium coadministration. It is not known whether this interaction occurs with other thyroid hormone preparations.
MANAGEMENT: Some experts recommend separating the times of administration of levothyroxine and calcium-containing preparations by at least 4 hours. Monitoring of serum TSH levels is recommended. Patients with gastrointestinal or malabsorption disorders may be at a greater risk of developing clinical or subclinical hypothyroidism due to this interaction.
References
- Schneyer CR (1998) "Calcium carbonate and reduction of levothyroxine efficacy." JAMA, 279, p. 750
- Singh N, Singh PN, Hershman JM (2000) "Effect of calcium carbonate on the absorption of levothyroxine." JAMA, 283, p. 2822-5
- Csako G, McGriff NJ, Rotman-Pikielny P, Sarlis NJ, Pucino F (2001) "Exaggerated levothyroxine malabsorption due to calcium carbonate supplementation in gastrointestinal disorders." Ann Pharmacother, 35, p. 1578-83
- Neafsey PJ (2004) "Levothyroxine and calcium interaction: timing is everything." Home Healthc Nurse, 22, p. 338-9
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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