Meropenem is a beta-lactam type antibiotic belonging to the class of carbapenems. It is a synthetic drug that - compared to imipenem (another antibiotic belonging to the class of carbapenems) - has a broader spectrum of action and a certain resistance against beta-lactamases (particular enzymes produced by some bacterial species whose function is to hydrolyse the beta-lactam ring, thus inactivating the antibiotic).
Meropenem - Chemical Structure
Furthermore, meropenem has a chemical structure that gives it resistance to the enzyme deidropeptidase-1 (an endogenous enzyme found in the kidney) which would otherwise degrade the antibiotic and prevent it from exerting its action. Resistance to this enzyme allows the administration of meropenem as a single drug, unlike imipenem which must always be administered in combination with an inhibitor of the aforementioned enzyme, cilastatin.
Indications
For what it uses
Meropenem is indicated for the treatment of infections caused by microorganisms sensitive to it. More precisely, meropenem is used to treat:
- Lung infections (pneumonia);
- Pulmonary and bronchial infections in patients with cystic fibrosis;
- Complicated abdominal infections;
- Acute bacterial infections of the brain (meningitis);
- Skin and soft tissue infections;
- Complicated urinary tract infections;
- Infections that can occur in women before, or after, giving birth.
Furthermore, meropenem can be used in the treatment of patients with leukopenia who experience fever caused by bacterial infections.
Warnings
Before taking meropenem it is necessary to inform your doctor if you have liver and / or kidney disease or if severe diarrhea has occurred after taking any other type of antibiotic.
Meropenem may alter the results of the Coombs test.
Interactions
Because of the possible interactions that could be established, it is necessary to inform the doctor if you are already taking probenecid (a drug used in the treatment of gout).
The concomitant administration of meropenem and valproate (a drug used to treat epilepsy) should be avoided, as meropenem plus decrease the therapeutic efficacy of valproate itself.
In any case, the doctor must still be informed if they are taking - or if they have recently been taken - drugs of any kind, including medicines without a prescription and homeopathic and / or herbal products.
Side effects
Meropenem can cause various types of side effects, although not all patients experience them. This is due to the different sensitivity that each individual has towards the drug. Therefore, it is said that the adverse effects do not all occur with the same intensity in each patient.
The following are the main side effects that can occur during treatment with meropenem.
Allergic reactions
Meropenem can trigger allergic reactions, even serious ones, in sensitive individuals. These reactions can manifest with symptoms, such as:
- Severe rashes;
- Itch;
- Urticaria;
- Swelling of the face, tongue, lips or other parts of the body;
- Difficulties and / or respiratory disorders;
- Wheezing.
Gastrointestinal disorders
Therapy with meropenem can cause nausea, vomiting, diarrhea, stomach pain or inflammation of the intestine accompanied by severe diarrhea.
Skin and subcutaneous tissue disorders
Treatment with meropenem can cause itching and even severe skin rashes.
Mushroom infections
Meropenem therapy can promote the onset of infections caused by fungi normally present in human bacterial flora. Examples of these infections are candidiasis in the oral cavity (thrush) and vaginal level.
Blood and lymphatic system disorders
Treatment with meropenem may cause:
- Increased number of platelets in the bloodstream;
- Eosinophilia, ie the increase in plasma concentration of eosinophils;
- Anemia;
- Plateletopenia (ie the decrease in the number of platelets in the bloodstream), with consequent increased risk of bleeding;
- Leukopenia, ie the reduction in the number of leukocytes in the bloodstream.
Your doctor may decide to prescribe regular blood tests.
Nervous system disorders
Therapy with meropenem can cause headaches, tingling sensation and convulsions.
Alterations in laboratory tests
Treatment with meropenem can alter the blood tests that determine the functioning of the kidneys and liver.
Site related disorders of administration
Administration of meropenem can cause pain at the vein in which the drug is injected.
Overdose
If you suspect an overdose of meropenem, you must immediately inform your doctor or nurse or go to the nearest hospital.
Action mechanism
Meropenem performs its antibiotic action by interfering with the synthesis of the bacterial cell wall, ie it interferes with peptidoglycan synthesis.
Peptidoglycan is a polymer made up of parallel chains of nitrogenated carbohydrates, joined together by transverse bonds between amino acid residues.
These bonds are formed thanks to the action of enzymes belonging to the peptidase family.
Meropenem - by binding to some of these peptidases - hinders the formation of the above transverse bonds. In this way, weak areas are created inside the peptidoglycan that lead to the lysis of the bacterial cell and, consequently, to its death.
Mode of Use - Posology
Meropenem is available for intravenous administration as a powder and solvent for solution for injection, which must be mixed just before the drug is used.
Meropenem is given as an intravenous injection or infusion, usually by a doctor or nurse.
Meropenem doses should be given at the same time every day.
The dosage of meropenem is established by the doctor depending on the type and severity of the infection to be treated.
Following are some indications on the doses of drug usually used in therapy.
Adults
In adults, the dose of meropenem usually administered ranges from 500 mg to 2 g of antibiotic. Usually, the dose is given every eight hours, but - in patients with kidney disease - the frequency of administration could be reduced.
Children and adolescents
In children from three months of age to 12 years of age, the dose of meropenem administered is 10-40 mg / kg of body weight. Usually, the drug is administered every eight hours.
In children with a body weight above 50 kg, the dose of meropenem administered is the same as that used in adults.
Pregnancy and breastfeeding
Before taking meropenem, pregnant women should seek medical advice. However, it is preferable to avoid the use of the drug during gestation.
Since meropenem is excreted in breast milk and may have effects on the baby, breast-feeding mothers should seek advice from their doctor before taking the antibiotic, who will decide whether the drug can be taken or not.
Contraindications
The use of meropenem is contraindicated in the following cases:
- Known hypersensitivity to meropenem or other carbapenems;
- Known hypersensitivity to other beta-lactam antibiotics, such as penicillins, cephalosporins or monobactams.
