antibiotics are well known to alter neuronal functioning , with penicillin being the best studied on not only a clinical level but on a basic science level as well .
after multiple reports emerged on the probable relation between high dose penicillin and seizure , detailed animal studies emerged that showed toxic doses of penicillin given intravenously could induce myoclonic jerks at the spinal level , and could be abolished by penicillinase administration .
given the wide spread use of structurally related antibiotics that share the beta lactam ring structure of penicillin , clinicians need to be aware of the potential for secondary neurotoxic effects .
this report describes reversible frequent myoclonic jerks of the extremities during intravenous administration of nafcillin with piperacillin .
a 66-year - old male who underwent a repeat knee prosthesis surgery developed pain and swelling at the operative site shortly afterwards with fever and elevation of the white blood count to 13,700 . for the treatment of staphylococcus warneri isolated from the operative site , intravenous antibiotics were given , with vancomycin started initially at a dose of 1.25 gm q8 hours , but then switched to a combination of nafcillin 2 grams 18 hours iv , plus piperacillin / tazobactam 4.5 grams q6h iv .
shortly after starting this regimen , the patient noted the onset of random myoclonic jerks of the extremities , which would be an isolated limb but at other times be all four limbs at once as a single isolated myoclonic jerk .
in addition , the patient reported something is wrong with my time clock and felt surprised that long periods of time had passed , and also had a spell of getting up to go to the bathroom , and feeling there was a gap in time .
approximately 40 random myoclonic jerks were estimated to occur over the course of each day of the six week course of the nafcillin / piperacillin combination by the patient and his wife , who stayed in the room , and noticed random jerks of the extremities also during sleep , which would awaken the patients at times .
electrolytes were stable with a sodium of 140 on the first day of myoclonic jerking with potassium normal at 3.8 , calcium normal at 8.9 , and magnesium normal at 2.10 .
a non - contrast computed tomography of the head was negative ( figure 1 ) .
past medical history was negative for any neurological problems , and there was no personal or family history for seizures or myoclonic jerks .
neurological exam revealed the patient to be fully oriented with accurate 4 of 4 complex object recall at 5 minutes , with normal deep tendon reflexes and normal muscle tone and strength .
the patient reported complete cessation of the myoclonic jerks after discontinuation of antibiotics , and has been free of this problem afterwards .
the presented case clearly illustrates the potential for patients to develop myoclonic jerks as a secondary adverse effects of piperacillin and/or nafcillin .
given the underlying pathophysiology of interaction of penicillin with the gamma - aminobutyric acid type a ( gaba - a ) receptor chloride channel , it is likely that these two antibiotics may interact in a similar way , and possibly reduce inward inhibitory chloride fluxes into both spinal and supra - spinal neurons .
piperacillin has been noted to not only induce an encephalopathy , but can also produce seizures as shown by lin et al . , who rapidly reversed this by high - flux hemodialysis in a 57 year old end stage renal disease patient who developed 2 generalized tonic - clonic seizures after five 250 mg doses of piperacillin / tazobactam an excellent study by sugimoto et al .
defined the pathophysiology of the ability of penicillin to produce seizure activity by reducing chloride currents across the gaba - a receptor gated channel . by inducing a selective mutation of tyrosine to phenylalanine at position 256 within the gene encoding the gaba - a receptor gated channel ,
this selective mutation of the beta 2 subunit rendered the altered gaba - a receptor insensitive to the pro - convulsant medication picrotoxin .
detailed voltage clamp study on frog oocytes transfected with these altered channels showed a dramatic inability for penicillin to reduce inhibitory currents .
in summary , clinicians need to be aware of the potential for triggering myoclonic activity with piperacillin and nafcillin .
as they are structurally similar to penicillin , these two antibiotics may place patients at risk as well for developing seizure activity .
the pathophysiology for these effects appear to be related to reducing inhibitory hyper - polarizing chloride currents across gaba - a receptor gated channels within the brain
 a 66-year - old male receiving intravenous piperacillin and nafcillin for a post - surgical wound infection developed intermittent myoclonic jerks of all four extremities that disappeared after discontinuation of these two medications . 
 in addition there was a mild yet definite intermittent encephalopathic effect ; head computed tomography examination as negative and there was no prior history for seizure or myoclonus . 
 these two beta lactam ring antibiotics are structurally similar to penicillin , which is well known to induce not only myoclonus but also seizure activity by reducing the gamma - aminobutyric acid ( gaba ) induced inhibitory currents by inducing an open chloride channel block of the gaba type a receptors within the brain . 
 clinicians need to be fully aware of the potential epileptogenic effects of piperacillin , nafcillin , and related antibiotics . 
Introduction
Case Report
Discussion
Conclusions