Cetix: composition and pharmaceutical form
Cetix comes in two forms. One film-coated tablet contains 400 mg of cefixime in the form of the trihydrate. The granules for the preparation of an oral suspension contain 100 mg of cefixime in 5 ml of the made-up suspension.
Both forms are intended for oral use only. The tablet is washed down with a sufficient amount of water, and the made-up suspension is given undiluted before or during a meal. A 5 ml plastic dosing syringe is supplied with the bottle — its volume corresponds exactly to 100 mg of cefixime. Food has no appreciable influence on the absorption of the medicine.
How Cetix works
Cefixime is an antibacterial medicine from the cephalosporin group. Like other cephalosporins, it binds to the penicillin-binding proteins and blocks their work. These proteins take part in the synthesis of the bacterial cell wall, so its construction is disrupted, the cell lyses and dies.
Bacterial resistance to cefixime can arise through several mechanisms at once: hydrolysis by extended-spectrum beta-lactamases or by the chromosomal AmpC enzymes, which in some aerobic Gram-negative bacteria can be induced or derepressed; a reduced affinity of the penicillin-binding proteins; a reduced permeability of the outer membrane, because of which the medicine reaches its target less well; and the work of pumps that actively expel the substance from the cell. In a single bacterial cell these mechanisms can combine, and then cross-resistance arises to several or to all the other beta-lactam antibiotics and to medicines of other groups.
Indications
Cetix is used in infections caused by microorganisms sensitive to it: sudden exacerbations of chronic bronchitis, acute otitis media, uncomplicated acute cystitis and uncomplicated pyelonephritis.
When prescribing an antibiotic the doctor is guided by the official recommendations on rational antibacterial therapy. This matters: the less often antibiotics are used without an indication, the more slowly bacterial resistance grows.
Method of use and dosage
Adults are recommended 400 mg a day — as a single dose or in two doses of 200 mg every 12 hours. Elderly patients are given the same dose as other adults, but with severe impairment of kidney function it is reviewed after the renal function has been assessed. The usual length of treatment is 7 days; if necessary the course is extended to 14 days.
| Group of patients | Dosage |
|---|---|
| Adults | 400 mg a day as a single dose or 200 mg every 12 hours |
| Adolescents from 12 years | The same dose as in adults |
| Children under 12 | The tablets are not used — the suspension is intended for them |
| Creatinine clearance of 20 ml/min and above | The standard dose and scheme |
| Creatinine clearance below 20 ml/min | No more than 200 mg once a day |
| Continuous ambulatory peritoneal dialysis and haemodialysis | As with a creatinine clearance below 20 ml/min |
The data on the use of cefixime in children and adolescents with renal failure are insufficient, so in this group the medicine is not recommended.
Contraindications
Cetix is not prescribed in hypersensitivity to cefixime, to other cephalosporin antibiotics or to any excipient of the medicine.
The second contraindication is a history of an immediate or severe hypersensitivity reaction to penicillin or to any other beta-lactam antibiotic. Between the penicillins and the cephalosporins there is a partial cross-allergy, and in such cases the risk is too high.
Special warnings and precautions
The main theme of the warnings is allergy. Cefixime is prescribed with caution to patients with hypersensitivity to other medicines, and particular caution is observed in those who have had an allergic reaction to penicillin or to another beta-lactam antibiotic in the past: severe reactions, including anaphylaxis, have been described to both groups of medicines. With a severe hypersensitivity reaction or an anaphylactic reaction the medicine is withdrawn at once and emergency measures are taken.
- with a creatinine clearance below 20 ml/min the medicine is used with caution;
- in children and adolescents with renal failure the data are insufficient, so cefixime is not recommended for them;
- with concomitant use of aminoglycosides, polymyxin B, colistin or high doses of loop diuretics, for example furosemide, kidney function is monitored: a further worsening of it is possible;
- diarrhoea during or after a course of antibiotic makes it necessary to bear in mind antibiotic-associated colitis;
- with prolonged use bacterial and fungal superinfection are possible;
- in some patients, as with other cephalosporins, a prolongation of the prothrombin time was noted — with anticoagulants caution is needed;
- the medicine can distort the results of laboratory tests, so glucose in the urine is measured by enzymatic methods with glucose oxidase;
- a false-positive direct Coombs test is possible, and also a false-positive result in the determination of ketone bodies if nitroprusside-based tests are used.
Drug interactions
Concomitant use with potentially nephrotoxic substances — aminoglycoside antibiotics, colistin, polymyxin and viomycin — or with powerful diuretics such as ethacrynic acid and furosemide raises the risk of impaired kidney function.
Nifedipine, a calcium channel blocker, is capable of raising the bioavailability of cefixime by almost 70%. As with other cephalosporins, a prolongation of the prothrombin time was noted in some patients, so with the concomitant use of anticoagulants caution is required. Separately one must remember the influence on tests: a false-positive result is possible in the determination of glucose in the urine with Benedict's and Fehling's reagents or with the copper sulfate tablet test — in those cases enzymatic tests with glucose oxidase are used, and for ketone bodies, instead of nitroprusside tests, tests with cyanonitrosoferrate are used.
Pregnancy and breastfeeding
There are no sufficient data on the use of cefixime in pregnant women. Animal studies revealed no direct or indirect harmful influence on the course of the pregnancy, the development of the embryo and the foetus, the birth and postnatal development. As a precaution the medicine is not used in pregnancy unless the doctor considers it necessary.
Whether cefixime passes into human breast milk is unknown; in preclinical studies in animals it was excreted in the milk. The decision on continuing breastfeeding or the treatment is taken by weighing the benefit of feeding for the child against the benefit of the therapy for the mother; however, until wider clinical experience has been accumulated the medicine is not prescribed to breastfeeding women. Studies of reproductive function in mice and rats showed no harmful influence on fertility.
Adverse effects
The most frequent undesirable reactions affect digestion and the skin.
- common — diarrhoea and rash;
- uncommon — abdominal pain, nausea, vomiting, headache, angioedema, itching;
- rare — flatulence, dizziness, loss of appetite, eosinophilia, hypersensitivity reactions, inflammation of the mucous membranes, fever;
- rare — bacterial and fungal superinfection;
- very rare — antibiotic-associated colitis;
- very rare — leucopenia, agranulocytosis, pancytopenia, thrombocytopenia, haemolytic anaemia;
- very rare — anaphylactic shock, serum sickness, psychomotor hyperactivity, hepatitis, cholestatic jaundice, interstitial nephritis;
- very rare — Stevens-Johnson syndrome and toxic epidermal necrolysis; frequency not known — drug rash with eosinophilia and systemic symptoms (DRESS syndrome), erythema multiforme, thrombocytosis, neutropenia.
Overdose
There is no experience of cefixime overdose. In healthy people taking up to 2 g of the medicine, the profile of undesirable reactions did not differ from that seen with the usual therapeutic doses.
In an overdose gastric lavage may be recommended. There is no specific antidote, and haemodialysis and peritoneal dialysis do not remove cefixime to any appreciable extent.
How to get a prescription for Cetix online
Cephalosporin antibiotics are dispensed on prescription: the doctor must be satisfied that the infection is bacterial and take into account any allergic reactions to penicillins and other beta-lactams in the past.
During the online consultation the doctor will go through the symptoms, the allergy history and the state of the kidneys, will determine the length of the course and, if there are indications, will issue an electronic prescription — the medicine can be collected from a pharmacy using its code.
