Alan Nathan examines the symptoms and OTC treatments for pain…

SCENARIO

Pharmacist Eve has taken on pre-registration pharmacist trainee Sanjay who has completed the first six months of his training in a hospital pharmacy.

He knows little about symptom management and OTC medicines, so Eve sets him an assignment to familiarise him with these in relation to pain.

She first asks him to draw up a list of minor ailments in which pain plays a characteristic or major role. She then asks him to write descriptions of the main clinical features of three of the conditions in his list - back pain, migraine and dysmenorrhoea.

Finally, Eve asks Sanjay to identify any constituents of OTC medicines that are licensed specifically and exclusively for particular conditions in which pain is a major feature.

QUESTIONS

1.What was the list that Sanjay came up with?

2.What are the main clinical features of back pain, migraine and dysmenorrhoea?

3.What are these constituents and what products contain them?

ANSWERS

1.Sanjay's list

•   Back pain

•   Cold sores

•   Dental pain

•   Dysmenorrhoea

•   Haemorrhoids

•   Earache

•   Headache

•   Migraine

•   Sports injuries

•   Verrucas

2. Main clinical features of;

Back pain

In many cases of back pain no cause can be determined. Where a mechanical cause  can be identified there are two main causes:

•   soft-tissue injury strain of spinal muscles and ligaments (lumbago, fibromyalgia),  often brought on by an event involving lifting or twisting. Pain may spread right across the back at the level of the top of the pelvic girdle, may run vertically on one side of the spine, or may radiate to the buttock or thigh. Pain and restriction of movement may cause the patient to adopt a posture of leaning forward or to one side.

•   trapping of a nerve root, usually the sciatic nerve, due to a slipped intervertebral disc (sciatica). Nerve root pain is felt in the lower back and often radiates down one leg, sometimes as far as the foot. It can be intense and burning, is constant and made worse by movement. The patient limps and is unable to flex the hip very far, making sitting and climbing stairs uncomfortable; gait is stiff and awkward, and patients may hold themselves rigid to avoid movement.

Migraine

The International Headache Society has defined migraine as a condition in which at least five headaches are experienced by a sufferer that are not attributed to another disorder, lasting 4 to 72 hours (untreated or unsuccessfully treated), with two or more of the following characteristics:

·      unilateral location (60%-70% of sufferers).

·      pulsating quality.

·      moderate or severe pain intensity.

·      aggravation by or causing avoidance of routine physical activity (e.g. walking, climbing stairs).

Plus one or more of the following symptoms during the headache:

·      nausea (occurs in 80%-90% of sufferers) and/or vomiting (40%-60%).

·      increased sensitivity to light (80%).


·      increased sensitivity to sounds (75-80%).

·      increased sensitivity to smells.

Other neurological symptoms experienced as a premonitory phase (aura), usually for up to an hour before the onset of headache, occur in about one-third of migraine sufferers include:

·      general light headedness- tingling or stiffness in the limbs.

·      an inability to concentrate.

·      difficulty in speaking.

·      visual disturbances.

·      in very rare cases, paralysis or loss of consciousness.

Dysmenorrhoea

There are two types of dysmenorrhoea:

•   Primary - painful menstruation in the absence of detectable pelvic pathology. It generally starts a year or so after menarche (the first period), once ovulatory cycles are established. Peak incidence is between 15 and 25 years of age, declines with age and does not occur after the birth of a first child.

- The main features are: crampy, colicky pain in the lower abdomen, which may radiate to the back of the legs or the lower back; onset within a day or two before the start of bleeding, until within a day or two after; there is no vaginal discharge; associated symptoms include nausea, vomiting, gastrointestinal discomfort, constipation, headache, backache, fatigue, faintness and dizziness. Symptoms can usually be treated with OTC medication.

•   Secondary - painful menstruation attributed to pelvic pathology. It is uncommon before the age of 25 years.

- The main features are:dull,continuous, diffuse abdominal pain, starting several days before the start of bleeding and continuing for several days after; there may be vaginal discharge (which may indicate pelvic infection); associated symptoms include backache, fatigue, menorrhagia (heavy periods) and dyspareunia (painful intercourse). Referral is necessary if secondary dysmenorrheoa is suspected.

3. Constituents of OTC analgesics licensed exclusively for particular conditions

Sumatriptan

Triptans are 5HT1D-receptor agonists that cause constriction of the cerebral arteries and counteract the cranial vasodilatation thought to be responsible for migraine attacks.

They are established as a first-line treatment for migraine. Sumatriptan 50mg tablets (Imigran Recovery), are licensed for pharmacy sale for acute relief of migraine attacks, with or without aura, in adults aged 18–65 years. The licensing conditions only permit supply if migraine has already been diagnosed by a doctor.

Treatment may not be supplied for prophylaxis. Sumatriptan should be avoided by patients taking selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, moclobemide, St John's wort and other vasoconstrictor migraine treatments, especially ergotamine and methysergide.

Isometheptene mucate

A sympathomimetic used in the treatment of migraine and throbbing headache for its vasoconstrictor effect. It is combined with paracetamol in one proprietary product (Midrid).

Prochlorperazine

Prochlorperazine maleate 3mg buccal tablets (Buccastem M) are licensed for the non-prescription treatment of nausea and vomiting associated with migraine.

The licensing conditions only permit supply if migraine has already been diagnosed by a doctor to adults of 18 years and over. It is contraindicated in pregnant and breastfeeding women and also in patients with impaired hepatic function, narrow-angle glaucoma, prostatic hypertrophy, epilepsy or Parkinson's disease.

Buclizine

Buclizine, an H1-receptor antagonist with anti-muscarinic properties, is included in Migraleve Pink tablets for its anti-emetic effect in the treatment of migraine.

Ibuprofen lysine

A salt of ibuprofen that is more readily soluble in water than ibuprofen and has a more rapid onset of action. It is available as Nurofen Migraine Pain tablets in two strengths, 342mg and 684mg (equivalent to ibuprofen 200mg and 400mg). It is licensed for the treatment of headache as well as migraine.

Naproxen

Naproxen 250mg tablets are marketed as Feminax Ultra and licensed for the relief of pain and cramps associated with menstruation. Supply is restricted to up to three tablets per day for a maximum of three days, to women aged between 15 and 50 years. Precautions are as for NSAIDs generally.