Article updated on 12 December 2023
Amoxicillin belongs to the category of antibiotics
It is a semi-synthetic molecule produced by the pharmaceutical company SmithKline Beecham, sold both as an active ingredient and in the form of tablets containing over amoxicillin also clavulanic acid. This antibiotic acts against gram negative and gram positive bacteria, inhibiting the synthesis of peptinoglucan, the main component of their cell wall.
Names by which amoxicillin is known on the market
L’amoxicillin it was first marketed in 1998 under the names Amoxicillin, Amoxil and Trimox. Over time, the antibiotic sector has evolved, giving rise to new names such as the famous Zimox, produced by the pharmaceutical company Pfizen and Agumentin, produced by GlaxoSmithKline. In addition to the two most famous commercial names we can mention Velamox, Sintopen, Sievert, Pamocil, Mopen, Amox and Amoflux based only on amoxicillin and Abba, Aklav, Anival, l ‘Aveggio, Clavulin, Neoduplamox and Puriclav which use the combined action amoxicillin/clavulanic acid.
General informations
Amoxicillin is an antibiotic similar to penicillin that differs in small structural differences. It has an extra hydroxyl group on the benzene ring and an amino group on the side chain. The presence of the NH2 group (amino group) hinders the ability of the beta-lactama enzymes to open the beta-lactam ring of the antibiotic, thus inhibiting the effect of the medicine.
Its spectrum of action is very broad and works for most bacterial infections. It is usually the first antibiotic chosen by the doctor, since it is absorbed by the body immediately after taking it orally. It is also well tolerated by children. The efficiency of the antibiotic is increased by the combined use of clavulanic acid, a powerful inhibitor of beta-lactamase enzymes.
L’ amoxicillin it is used in the treatment of many pathologies, from the most complex to the common ones. For example, it is recommended as an antibiotic in the eradication of Helicobacter pylori, in case of pharyngitis and laryngitis caused by streptococci, in all urinary tract infections such as cystitis, urethritis, pyelonephritis and gonorrhea, in pneumonia, in soft tissue infections and of the skin. Amoxicillin is also recommended for preventing bacterial endocarditis in people undergoing dental procedures and in preventing the onset of Streptococcus pneumoniae infections in people without a spleen.
Dosage
In adults, the administration of one 1 g tablet every 8/12 hours is recommended, according to the opinion of the treating doctor. The administration of the drug should absolutely not be suspended immediately after fever or recovery, but must be continued up to 48 hours later.
In children weighing less than 40 kg the recommended dose is 40-90 mg/kg/day in two or three administrations. Children exceeding 40 kg of body weight must follow the same dosage as adults.
In the case of tonsillitis, ear infections, Lyme disease and endocarditis prophylaxis it is necessary to proceed with a special recommended dosage. For tonsillitis the recommended quantity is 750-1500 mg/day in three administrations for a total treatment time of 7-10 days. Early Lyme disease follows therapy with 1.5 g in three divided daily doses for 14 to 21 days. Endocarditis prophylaxis involves the administration of 2 g of amoxicillin, taken in a single dose one hour before surgery.
For the eradication of Helicobacter pylori in triple therapy, the recommended dose is 2 g per day to be divided into two daily administrations. For actinomycosis the quantity of amoxicillia to be taken is 1.5 g per day in three administrations for a total treatment duration of six months.
The dose of amoxicillin to be used as prophylaxis against anthrax in adults is 500 mg every 8 hours while in children it is 80 mg/kg/day, divided into 4 equal doses to be administered every 8 hours.
In the treatment of bacterial cystitis, the dose to be taken is 750-1500 mg/day, divided into three daily doses for 3-7 days.
Side effects
About 30% of patients use amoxicillin suffer from side effects. Among the side effects that occur most frequently are skin rash, erythema, anaphylaxis, anemia and thrombocytopenia. These side effects resolve spontaneously following discontinuation of treatment. Additional consequences resulting from the use of amoxicillin are:
Diarrhea Nausea Stomatitis Vomiting Altered platelet function Increased liver transaminases Jaundice Reversible agranulocytosis
Contraindications and interactions
The assimilation of amoxicillin is fast but is slowed down by the presence of food in the stomach, without absorption paying the consequences. Its bioavailability varies between 70% and 90%. Absorption occurs in the intestinal lumen via carriers that transport dipeptides.
The active ingredient can cause allergic reactions and hypersensitivity. If side effects occur, it is best to stop treatment immediately. Subjects who have already demonstrated hypersensitivity to imipenem and cephalosporins, or who suffer from asthma and eczema of allergic origin, must pay particular attention.
The use of amoxicillin against Chlamydia in pregnant women, requires a check-up three weeks after the end of treatment. It is also necessary to carry out further checks between the 36th and 40th gestational weeks, so as to ensure complete recovery.
Administration of the antibiotic in patients suffering from colitis can cause an aggravation of side effects. If severe diarrhea occurs, a test should be performed to ensure that it is antibiotic-induced pseudomembranous colitis. If the test result is positive, you should stop taking the antibiotic and ask your doctor for advice.
Subjects who measure glucose in their urine, and who follow a therapy based on amoxicillinthey must communicate this to the testing laboratory, since the drug could induce false positives.
In particular, women who use oral contraceptives must pay attention, since the antibiotic reduces the absorption of hormones. For this reason, during the period of treatment with amoxicillin it is recommended to use additional contraceptive measures.
Pregnancy and breastfeeding
To date, specific studies on the use ofamoxicillin during pregnancy and breastfeeding were not conducted. Tests carried out on animals have shown that there is no risk to the fetus. The administration of the antibiotic during breastfeeding does not cause problems for the baby, remaining in doses of 1 gram per day. In some cases, however, since amoxicillin is excreted in breast milk, the baby may experience disturbances to the intestinal flora.