Interactions : אינטראקציות

4.5 Interaction with other medicinal products and other forms of interaction
Muscle relaxants and ether
The neuromuscular blocking activity of aminoglycosides is enhanced by ether and muscle relaxants.

If gentamicin is administered during or immediately after surgery, the neuromuscular blockade may be enhanced and prolonged if non-depolarising muscle relaxants are used.
These interactions may cause neuromuscular blockage and respiratory paralysis. Because of the increased risk, such patients should be monitored with particular care.

Injection with calcium chloride may reverse the neuromuscular blockade due to aminoglycosides but should be undertaken with caution.

Methoxyflurane anaesthesia
Aminoglycosides may increase the kidney damaging effect of methoxyflurane. When used concurrently, extremely severe nephropathies are possible. The anaesthetist should be made aware of the use of aminoglycosides before a surgical procedure.

Potentially nephrotoxic or ototoxic drugs
Concurrent administration of gentamicin and other potentially ototoxic or nephrotoxic drugs should be avoided whenever possible. Where co- administration is considered necessary, because of the increased risk of undesired effects, careful monitoring is required of patients being treated concurrently or sequentially with potentially nephrotoxic or ototoxic drugs such as:

- Antibacterials: some cephalosporins, notably cephalotin and cephaloridine, colistin, vancomycin, viomycin, other aminoglycosides such as streptomycin

- Antifungals: amphotericin B

- Loop diuretics such as ethacrynic acid and furosemide
- Cytotoxics: cisplatin. It must be noted that the nephrotoxicity of gentamicin can be increased even 3 to 4 weeks after these substances are administered.

- Anti suppressant: ciclosporin

Other antibiotics
A reduction in gentamicin serum half-life has been reported in patients with severe renal impairment receiving carbenicillin concomitantly with gentamicin.

Indometacin
Indometacin possibly increases plasma concentrations of gentamicin in neonates.

Oral anticoagulants
Concurrent use with oral anticoagulants may increase the hypothrombinanaemic effect.
Bisphosphonates
Concurrent use of bisphosphonates may increase the risk of hypocalcaemia.

Cholinergics
Antagonism of effect may occur with concomitant administration of gentamicin with either neostigmine or pyridostigmine.
Concurrent use of botulinum toxin and gentamicin may increase the risk of toxicity due to enhanced neuromuscular block.