Baclofen increased tolerance

A second major concern is the possibility that tolerance could develop with long-term, continuous baclofen administration. Tolerance is the need for more of a drug to achieve its beneficial effects when used for prolonged periods. Several studies have reported that dosage must indeed be increased progressively when intrathecal baclofen systems are used for periods of several months to several years.40,63 Tolerance to intrathecal baclofen, however, can usually be dealt with by periodic adjustments in dosage, and tolerance does not usually develop to such an extent that intrathecal baclofen must be discontinued. 

Baclofen is at least as effective as diazepam in reducing spasticity and causes less sedation. In addition, baclofen does not reduce overall muscle strength as much as dantrolene. It is rapidly and completely absorbed after oral administration and has a plasma half-life of 3-4 hours. Dosage is started at 15 mg twice daily, increasing as tolerated to 100 mg daily. Adverse effects of this drug include drowsiness however, patients become tolerant to the sedative effect with chronic administration. Increased seizure activity has been reported in epileptic patients. Therefore, withdrawal from baclofen must be done very slowly. 

Tizanidine is in general better tolerated by patients compared with baclofen and diazepam. In a comparative review of different muscle relaxants, Chou et aL [5] reviewed 101 trials and concluded that baclofen and tizanidine are equally effective in treating patients with spasticity, though tizanidine is more often associated with dry mouth, while baclofen causes increased weakness. 

Drug tolerance In a retrospective study in 37 patients treated with intrathecal baclofen, the dose increased in the first 18 months after implantation and then stabilized around a mean dose of 350 micrograms/ day [43 ]. Eight patients developed tolerance, defined as a dose increase of over... 

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