There is an excellent medical centre in Los Alcazares which I think is closer than the one in San Javier, its certainly easier to find being on the main road through the town, it is on the left hand side near the Farmacia, before the Ramblas where the Tuesday market is situated.
There is also a dentist here for those who may need one.
There is a doctors surgery situated near the Tobacconist in Los Narejos, near to the Farmacia where there is an excellent English speaking German guy working.
Best Regards
Dale