Baclofen: Efficacious Muscle Relaxant with Long-Term Safety

US FDA APPROVED since January 20, 1982
INDEX:

1. Description
2. Mechanism of Action/ How Does it work
3. Indication
4. Dosage and Administration
5. Special Features
6. Available Brands

Description:

Baclofen, a centrally acting skeletal muscle relaxant. A gamma-aminobutyric acid derivative and GABAB receptor agonist.

How does it work(Mechanism of Action):

• Baclofen, inhibits monosynaptic and polysynaptic reflexes at the spinal level by hyperpolarization of afferent terminals.
• Baclofen, enhances the activities of the inhibitory neurotransmitter GABA and Glycin
• Baclofen, decreases the release of the excitatory neurotransmitter Aspartate and Glutamate
• Baclofen, also shows antinociceptive effects
• Baclofen, also shows inhibitory effects on Serotonin ( a polypeptide; works like excitatory neurotransmitter) 

Indications (Rx):

1. Spasticity
2. Muscle spasm
3. Muscular rigidity
4. Low back pain
5. Intractable hiccups
6. Trigeminal neuralgia
7. Dysfunctional voiding
8. GERD
9. Tension type headache
10. Migraine
11. Cluster headache

Dosage and Administration:

Start therapy from the lowest possible dose and gradually increase to achieve optimum result.

Following titration schedule is suggested-

05 mg t.i.d. for 3 days

10 mg t.i.d. for 3 days

15 mg t.i.d. for 3 days

20  mg t.i.d. for 3 days

The total dose should not exceed the maximum of 80 mg daily ( 20 mg q.i.d.)

Special features:

• Safe up to 6 years (long term treatment for spastic disorders)
• Highly effective due to effects on both Glycine and GABA
• Higher bio-availability (70-80%) ensures higher clinical effect
• Very low stress on liver due to low metabolism ( 15 %) on liver
• Devoid of dry mouth and sedation
• Free from Tolperisone like bad smell
• Co-administration with Ciprofloxacin and oral contraceptives is feasible.

Superior to other muscle relaxants:

Superior to Tolperisone

Tolperisone has some limitations which can be overcome by Baclofen -

• Baclofen works by
• Inhibiting excitatory neurotransmitters &
• Increasing the inhibitory neurotransmitter.
• So, ensures faster relief from acute muscle spasm & pain.
• Baclofen has higher tolerability than Tolperisone
• Baclofen has more clinical experience (which includes clinical trial over 6 yrs) than Tolperisone.
• Baclofen shows higher bioavailability (70-80%) than Tolperisone (20%).
• Baclofen exerts minimum stress on liver than Tolperisone because only 15% of Baclofen is metabolized whereas Tolperisone is extensively metabolized by liver.
• Baclofen is devoid of urea like bad odor like Tolperisone.

 Superior to Tizanidine

Tizanidine has some limitations which can be overcome by Baclofen-

• Baclofen is more effective in muscle spasm than Tizanidine because
• Baclofen increases the activity of both GABA and glycine but Tizanidine increases only glycine.
• Baclofen shows higher bioavailability (70-80%) than Tizanidine (40%).
• Baclofen has no contraindication like Tizanidine with Ciprofloxacin or other fluoroquinolone, oral contraceptives. 
• Baclofen exerts minimum stress on liver than Tizanidine because only 15% of Baclofen is metabolized by liver whereas 95% of Tizanidine is metabolized.
• Baclofen, only muscle relaxant, has recommendation for long term use.
• Baclofen has more clinical experience (which includes clinical trial over 6 yrs) than Tizanidine.
• Baclofen does not produce dry mouth like Tizanidine.

Available Brands:

1. Lioresal- Novartis
2. Flexibac- Beacon Pharmaceuticals Ltd.,Bangladesh
3. Beklo- Opsonin Pharma Ltd., Bangladesh
4. Flexifen- Incepta Pharmaceuticals Ltd., Bangladesh
5. Fenobac- Sk+f Bangladesh Ltd.
6. Myorel- Healthcare Pharmaceuticals Ltd.