FOR MYASTHENIA GRAVIS, TOTAL DAILY DOSES IN THE UK MAY RANGE FROM 300 MG TO 1.2 G BY MOUTH; HOWEVER, THE BNF STATES THAT DAILY DOSES OF 450 MG SHOULD NOT BE EXCEEDED IN ORDER TO AVOID RECEPTOR DOWNREGULATION. IT ALSO NOTES THAT PATIENTS RECEIVING PYRIDOSTIGMINE IN DOSES OVER 360 MG DAILY MAY NEED MORE AGGRESSIVE THERAPY. IN THE USA, LICENSED DOSES ARE SOMEWHAT HIGHER, RANGING UP TO 1.5 G DAILY.
THE DOSE SHOULD BE DIVIDED THROUGHOUT THE DAY AND, IF NECESSARY, THE NIGHT ACCORDING TO THE RESPONSE OF THE PATIENT; LARGER PORTIONS OF THE TOTAL DAILY DOSE MAY BE GIVEN AT TIMES OF GREATER FATIGUE.
A SUGGESTED ORAL DOSE IN THE USA FOR CHILDREN IS 7 MG/KG DAILY IN 5 OR 6 DIVIDED DOSES. AN ALTERNATIVE REGIMEN USED IN THE UK IS AN INITIAL DOSE OF 30 MG FOR CHILDREN UNDER 6 YEARS OR 60 MG FOR THOSE AGED 6 TO 12 YEARS. THIS IS INCREASED GRADUALLY BY INCREMENTS OF 15 TO 30 MG DAILY UNTIL A SATISFACTORY RESPONSE IS OBTAINED, WHICH IS USUALLY WITHIN THE DOSAGE RANGE OF 30 TO 360 MG DAILY.
PYRIDOSTIGMINE HAS ALSO BEEN GIVEN AS MODIFIED-RELEASE TABLETS, USUALLY ONCE OR TWICE DAILY BUT THESE OFFER LESS FLEXIBILITY OF DOSAGE. IF NECESSARY IT HAS ALSO BEEN GIVEN BY INTRAMUSCULAR INJECTION OR IN SEVERE CASES BY VERY SLOW INTRAVENOUS INJECTION. HOWEVER, THE INTRAVENOUS ROUTE IS HAZARDOUS AND, IF USED, ATROPINE MUST BE AVAILABLE TO COUNTERACT ANY SEVERE MUSCARINIC REACTIONS.
IN THE TREATMENT OF NEONATAL MYASTHENIA DOSES IN THE RANGE OF 50 TO 150 MICROGRAMS/KG BY INTRAMUSCULAR INJECTION OR 5 TO 10 MG BY MOUTH (30 TO 60 MINUTES BEFORE FEEDS) HAVE BEEN GIVEN EVERY 4 TO 6 HOURS. ALTERNATIVELY, ORAL DOSES MAY BE BASED ON NEONATAL WEIGHT: IN THE UK, THE BNFC RECOMMENDS AN INITIAL DOSE OF 1 TO 1.5 MG/KG, INCREASED GRADUALLY TO A MAXIMUM OF 10 MG AND REPEATED THROUGHOUT THE DAY. TREATMENT IS RARELY NEEDED BEYOND 8 WEEKS OF AGE.
TO REVERSE NEUROMUSCULAR BLOCKADE PRODUCED BY COMPETITIVE NEUROMUSCULAR BLOCKERS, DOSES OF 10 TO 20 MG HAVE BEEN GIVEN INTRAVENOUSLY, WITH OR PRECEDED BY ATROPINE SULFATE 0.6 TO 1.2 MG TO COUNTERACT ANY MUSCARINIC EFFECTS. GLYCOPYRRONIUM BROMIDE HAS BEEN USED AS AN ALTERNATIVE TO ATROPINE.
IN THE USA PYRIDOSTIGMINE IS LICENSED FOR PROPHYLAXIS AGAINST THE NEUROMUSCULAR EFFECTS OF THE NERVE GAS POISON SOMAN IN MILITARY COMBAT USE ONLY; THE RECOMMENDED DOSE IS 30 MG BY MOUTH EVERY 8 HOURS STARTED AT LEAST SEVERAL HOURS BEFORE EXPOSURE TO SOMAN. IF NERVE GAS POISONING OCCURS, PYRIDOSTIGMINE SHOULD BE STOPPED AND THE PATIENT SHOULD BE TREATED WITH ATROPINE AND PRALIDOXIME IMMEDIATELY.
IN THE TREATMENT OF PARALYTIC ILEUS AND POSTOPERATIVE URINARY RETENTION PYRIDOSTIGMINE BROMIDE HAS BEEN GIVEN BY MOUTH IN DOSES OF 60 TO 240 MG.
PARASYMPATHOMIMETICS SUCH AS PYRIDOSTIGMINE ENHANCE GASTRIC CONTRACTIONS AND INCREASE INTESTINAL MOTILITY; THEY HAVE BEEN USED IN CONDITIONS ASSOCIATED WITH DECREASED GASTROINTESTINAL MOTILITY.
PYRIDOSTIGMINE, GENERALLY IN DOSES OF 60 MG UP TO 3 TIMES DAILY, HAS BEEN USED TO RELIEVE SEVERE CONSTIPATION IN PATIENTS WITH IMPAIRED INTESTINAL MOTILITY DUE TO PARKINSON'S DISEASE.