A healthcare provider may prescribe naproxen and cyclobenzaprine together, but this combination requires strict medical guidance due to significant interaction risks. The combination is typically reserved for short-term treatment, often two to three weeks, of acute conditions like a muscle sprain or low back pain where both inflammation and muscle spasm are present. While effective for comprehensive relief, the risks must be weighed carefully against the benefits for each patient. Combining these medications increases the potential for serious side effects, particularly involving the nervous and digestive systems.
Individual Roles of Naproxen and Cyclobenzaprine
Naproxen is a nonsteroidal anti-inflammatory drug (NSAID), commonly available under brand names like Aleve or Naprosyn. This medication works by inhibiting specific enzymes, known as cyclooxygenases, which produce prostaglandins—compounds that promote inflammation, pain, and fever. By reducing prostaglandin production, naproxen effectively decreases swelling and dulls pain signals from conditions such as arthritis or general muscle and joint disorders.
Cyclobenzaprine (Flexeril) is a centrally acting muscle relaxant. It is approved for the short-term treatment of muscle spasms associated with acute, painful musculoskeletal conditions. Its action occurs primarily within the central nervous system, likely in the brain stem, where it reduces excessive muscle hyperactivity without directly affecting muscle function. Physicians prescribe these drugs together to address both inflammatory pain (naproxen) and involuntary muscle spasms (cyclobenzaprine) from an injury.
Understanding Central Nervous System Depression
Cyclobenzaprine is a central nervous system (CNS) depressant, which means it slows down brain activity. The most common side effects from this action are drowsiness, dizziness, and dry mouth. When combined with other CNS depressants, such as alcohol or certain other medications, these sedative effects can become dangerously amplified.
This additive CNS depression impairs judgment, thinking, and coordination. Heightened sedation means activities requiring alertness, like driving or operating heavy machinery, become unsafe. In severe cases, excessive CNS depression can cause profound confusion, difficulty staying awake, or slowed and shallow breathing. This risk is the primary reason the combination requires careful monitoring by a healthcare provider.
Gastrointestinal and Other Safety Concerns
While cyclobenzaprine is the main contributor to sedation, naproxen introduces serious safety concerns involving the digestive tract. As an NSAID, naproxen interferes with protective mechanisms in the stomach lining, which increases the risk of serious gastrointestinal adverse events. These risks include inflammation, ulcers, bleeding, and potentially fatal perforation of the stomach or intestines.
The risk of a serious gastrointestinal bleed is higher for older adults, those with a history of ulcers or bleeding, and patients using the medication for prolonged periods. Taking naproxen with food can help reduce stomach irritation. The combination of medications can also strain the liver and kidneys, which are responsible for processing and eliminating drugs from the body.
When to Contact Your Healthcare Provider
Contact your healthcare provider immediately if you experience signs of a gastrointestinal bleed. These signs include severe abdominal pain, vomiting material that looks like coffee grounds, or passing black, tarry stools. These symptoms suggest internal bleeding and require urgent medical attention.
Seek emergency help if you notice signs of severe central nervous system depression, such as extreme confusion, difficulty waking up, or slow and shallow breathing. Contact your doctor if side effects like drowsiness, dizziness, or dry mouth become severe or do not improve. Never change the dosage or discontinue treatment without first consulting the prescribing physician, and ensure they are aware of all other medications and supplements you are taking.