MIRTAZAPINE (brand name Remeron) is a tetra-cyclic antidepressant. Though it is usually prescribed for major depression, there are many off-label uses, most notably to improve sleep-architecture in those with severe and/or chronic insomnia. It also posses anti-nausea, appetite-stimulating, antihistamine, anti-anxiety and strongly sedating properties, et al., though these become less noticeable with time. A notable irony is that at lower doses (<30mg) the sedative properties are greater than at higher doses (>45mg). The reason for this is, at low doses mirtazapine binds mostly with the brain's H1 receptor (the same receptor for which the sedating antihistamines have a strong affinity). At higher doses, however, mirtazapine begins to have a stimulating effect (due to the antagonizing of the alpha-2 adrenergic receptor) which partially offsets the sedative properties.

The initial dose is usually 30mg, and is adjusted based upon the patient's response to therapy; 90mg is the usually the highest recommended dose, although in severe cases, doses as high as 120mg have been found most efficacious.

Treatment for major depression with mirtazapine is recommended to continue for at least four months to gain maximum benefit. Stopping the medicine too soon can cause a return to the depressive state. If side effects are bothering you, do not stop taking mirtazapine; contact your doctor, the dose likely needs adjustment.

Mirtazapine must be discontinued very gradually and under close doctor supervision, as physical dependence will develop over time; this is especially important for patients who have used the drug at high doses and/or for long periods of time. Suddenly stopping mirtazapine may cause severe depression, insomnia, anxiety, panic attacks, (all dysphoric states) loss of appetite, worsening of allergies and rarely, manic episodes.

PJF

Your back pain may not go away completely, or it may get more painful at times. Learning to take care of your back at home and how to prevent repeat episodes of back pain can help you avoid surgery.

A number of different medications can also help with your back pain.

Over-the-counter pain relievers

Over-the-counter pain relievers can help with your back pain. Over-the-counter means you can buy them without a prescription.

Most doctors recommend acetaminophen (such as Tylenol) first, because it has fewer side effects than other drugs. Do not take more than 4 grams (4,000 mg) on any one day or 24 hours. Overdosing on Tylenol can cause severe damage to your liver.

If your pain continues, your doctor may suggest nonsteroidal anti-inflammatory drugs (NSAIDs). You can buy some NSAIDs, such as ibuprofen and naproxen, without a prescription. Anti-inflammatory drugs help reduce the swelling around the swollen disc or arthritis in the back.

Both NSAIDs and acetaminophen in high doses, or when taken for a long time, can cause serious side effects. Side effects may include stomach ulcers or bleeding, and liver or kidney damage. For NSAIDs, the common side effect is stomach pain or bleeding. If this occurs, stop taking the medicine right away and tell your health care provider.

If you are taking pain relievers for more than a week, tell your doctor. You may need to be watched for side effects.

Narcotic pain relievers

Narcotics, also called opioid pain relievers, are used only for pain that is severe and is not helped by other types of painkillers. They work well for short-term relief. Limit their use to no more than 3 to 4 weeks. These medicines are only rarely used to treat someone with chronic pain.

Narcotics work by binding to receptors in the brain, which blocks the feeling of pain. These drugs can be abused and addictive. When used carefully and under a doctor's direct care, they can be effective at reducing pain.

Examples of narcotics include:

• Codeine
• Fentanyl (Duragesic) - available as a patch
• Meperidine (Demerol)
• Morphine (MS Contin)
• Oxycodone (Oxycontin, Percocet, Percodan)
• Tramadol (Ultram)

Possible side effects of these drugs include:

• Drowsiness
• Impaired judgment
• Nausea or vomiting
• Constipation
• Itching

When taking narcotics, do not drink alcohol, drive, or operate heavy machinery.

Muscle Relaxants

Sometimes, your doctor will prescribe a group of drugs called muscle relaxants. Despite their name, they do not work directly on muscles. Instead, they work through your brain and spinal cord.

They are often given along with over-the-counter pain relievers to relieve the symptoms of back pain or muscle spasm.

Examples of muscle relaxants include:

• Carisoprodol (Soma) - may be more addictive than others
• Cyclobenzaprine (Flexeril)
• Diazepam (Valium)
• Methocarbamol (Robaxin)

Side effects from muscle relaxants are common and include drowsiness, confusion, nausea. and vomiting.

These medicines can be addictive. Talk to your doctor before using these drugs, as they may interact with other medicines or make certain medical conditions worse.

You should not drive or operate heavy machinery while taking muscle relaxants. You should also not drink alcohol while taking these medications.

Antidepressants

Antidepressants are normally used to treat people with depression. However, low doses of these medicines can help people with chronic low back pain -- even if they do not feel sad or depressed.

Antidepressant medicines work by changing the levels of certain chemicals in your brain. This changes the way your brain notices or perceives pain. The antidepressants most commonly used for chronic low back pain also will help you sleep.

Antidepressants most often used for back pain are:

• Amitriptyline (Elavil, Endep)
• Amoxapine (Asendin)
• Desipramine (Norpramin)
• Doxepin (Sinequan)
• Imipramine (Tofranil)
• Maprotiline (Ludiomil)
• Nortriptyline (Pamelor, Aventyl)

Common side effects of these medicines include dry mouth, constipation, blurred vision, weight gain, sleepiness, problems urinating, and sexual problems. Less commonly, these drugs can also have bad effects on the heart and lungs.

Do not take these drugs unless you are under the care of a doctor. Do not stop taking these drugs suddenly or change the dose without also talking with your doctor.

Anti-seizure or anticonvulsant medicines

Anticonvulsant medicines are used to treat people with seizures or epilepsy. They work by causing changes in the electric signals in the brain. They work best for pain that is caused by nerve damage.

These drugs may help some patients whose long-term back pain has made it hard for them to work, or that interferes with their daily activities.

The anticonvulsants most often used to treat chronic pain are:

• Carbamazine (Tegretol)
• Gabapentin (Neurontin)
• Lamotrigine (Lamictal)
• Pregabilin (Lyrica)
• Valproic acid (Depakene)

All of these drugs have their own side effects. However, common side effects include weight gain or weight loss, upset stomach, loss of appetite, skin rashes, drowsiness or feeling confused, and headaches.

Do not take these drugs unless you are under a doctor's care. Do not stop taking these drugs suddenly or change the dose without also talking with your doctor.

Chou R, Qaseem A, et al. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147(7):478-491.

Chou R, Atlas SJ, Stanos SP, Rosenquist RW. Nonsurgical interventional therapies for low back pain: a review of the evidence for an American Pain Society clinical practice guideline. Spine. 2009;34(10):1078-93.

Review Date: 06/04/2011

C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.