Damien O’Brien MPSI writes about migraine, its effect on quality of life, the importance of proper assessment, and therapeutic options
Introduction
Migraine is a chronic neurological disorder characterised by episodic attacks of moderate to severe headache accompanied by sensory and systemic symptoms. It affects approximately 12-15 per cent of the population and represents a significant cause of reduced quality of life, work absenteeism, and healthcare utilisation.
Migraine is approximately three times more prevalent in women than in men and commonly presents in adolescence or early adulthood, although individuals across all age groups may be affected. Despite its high prevalence and impact on daily life, migraine remains frequently underdiagnosed and undertreated, with many individuals relying on suboptimal self-management strategies or inappropriate medication use.
Migraine attacks often significantly impair daily functioning, with symptoms extending beyond headache to include nausea, vomiting, sensory sensitivity, and cognitive disturbances. Improved understanding of migraine as a complex neurological disorder has led to important advances in targeted therapies in recent years.
Community pharmacists are often the first healthcare professionals consulted by patients experiencing recurrent headaches. Pharmacists are therefore ideally positioned to recognise migraine, guide appropriate acute treatment, identify medication overuse, support patients receiving preventive therapies, and counsel on non-pharmacological interventions.
This article examines the clinical features, underlying pathophysiology and management of migraine,
with particular emphasis on pharmacological treatment strategies and the role of the pharmacist in optimising patient care.
Pathophysiology
The exact mechanisms underlying migraine are complex and multifactorial, involving genetic, vascular, and neurological components. Dysfunction of the trigeminovascular pathway plays a central role. Stimulation of trigeminal sensory nerves leads to the release of inflammatory neuropeptides such as calcitonin gene-related peptide (CGRP), substance P, and neurokinin A.
This cascade plays a key role in migraine pathogenesis by promoting vasodilation, neurogenic inflammation, and enhanced transmission of pain signals to the brainstem. Central sensitisation also contributes significantly to migraine. Increased excitability within the brainstem and cortical regions
results in amplification of sensory input, explaining associated features such as photophobia and phonophobia.
Genetic factors play an important role in migraine susceptibility, with up to 50 per cent of first-degree relatives of migraine sufferers affected. Specific gene mutations have been identified in familial hemiplegic migraine, illustrating the hereditary basis of the disorder. Genetic predisposition likely interacts with environmental and physiological triggers to initiate attacks.
Migraine attacks are often precipitated by identifiable triggers, which may vary considerably between individuals. Commonly reported triggers include stress, sleep disturbance, missed meals, dehydration, hormonal fluctuations, alcohol consumption, and sensory stimuli such as bright lights or strong odours.
Clinical presentation
Migraine typically presents as a pulsating, unilateral headache of moderate to severe intensity lasting from four to 72 hours. The pain is often accompanied by nausea, vomiting, photophobia, phonophobia, and osmophobia, and is worsened by physical exertion.
Migraine is a debilitating neurological condition involving complex and recurrent events that can significantly impair quality of life. Patients may experience anxiety, reduced social participation, and impaired concentration between attacks. Clinical presentation may vary between individuals and even between attacks in the same patient. Migraine commonly follows four distinct phases:
- Prodrome: Occurs hours to days before headache onset, with symptoms of fatigue, irritability, mood changes, food cravings, difficulty concentrating, and yawning.
- Aura: Present in approximately 25 per cent of cases, lasting from five to 60 minutes. It consists of transient neurological disturbances such as visual changes (flashing lights or temporary visual field loss), sensory symptoms (tingling or numbness) or speech disturbances. It is fully reversible and can precede or accompany the headache phase.
- Headache phase: The main symptomatic period, often disabling and typically lasting between four and 72 hours if untreated. Headache pain is often unilateral, pulsating and moderate to severe in intensity, worsened by activity and often accompanied by nausea, vomiting, photophobia, and phonophobia.
- Postdrome: Occurs following headache resolution and may last up to 24 to 48 hours. It is characterised by movement- sensitive pain in the same location as the headache, with other symptoms including exhaustion, dizziness, reduced concentration, and euphoria.
Assessment
Migraine is primarily a clinical diagnosis, based on characteristic symptom patterns rather than imaging or laboratory testing. The International Classification of Headache Disorders (ICHD-3) provides diagnostic criteria based on these features. The diagnosis
Early and appropriate treatment is associated with improved outcomes
of chronic migraine requires headache on at least 15 days per month for more than three months, with migraine features on at least eight days per month.
Neuroimaging is not routinely indicated unless atypical or red-flag symptoms are present. These may include new-onset headache in patients aged 50 years or older, systemic or meningeal signs, new neurological deficits, headache not responding to standard treatment, duration beyond 72 hours or significant changes in the frequency, pattern, or severity of attacks.
Acute management
The primary objective of acute migraine treatment is to achieve rapid and consistent relief of pain and associated symptoms, and restoration of function with minimal adverse effects. Treatment should be individualised to each patient according to attack severity, associated symptoms, comorbidities, and prior response. Early and appropriate treatment is associated with improved outcomes. A stepwise approach is generally recommended, progressing from simple analgesics to migraine-specific therapies as required. Using adequate doses is important, as subtherapeutic dosing is a common reason for treatment failure. Pharmacists play an important role in ensuring correct medicine selection, optimising timing of administration and referring patients when necessary.
Analgesics
Analgesics form the cornerstone of acute management for many mild to moderate migraine attacks and are widely accessed through community pharmacy. Paracetamol is often used as an initial option due to its favourable safety profile. It may be effective when taken early in an attack, particularly in combination with rest and hydration. However, efficacy may be limited in moderate to severe migraine.
Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin-mediated inflammation and pain. NSAIDs are generally more effective than paracetamol due to their anti-inflammatory action. Common NSAIDs include ibuprofen, aspirin, naproxen, and diclofenac. Gastrointestinal toxicity, renal impairment, hypertension, and increased cardiovascular risks are potential adverse effects associated with NSAID use, particularly with prolonged use at high doses. Combination therapy with paracetamol and an NSAID may provide greater analgesic efficacy.
Triptans
Triptans are a migraine-specific therapy, often indicated for moderate to severe migraine or attacks unresponsive to analgesics. They act as agonists at serotonin 5-HT1B and 5-HT1D receptors in cranial blood vessels and nerve terminals, causing vasoconstriction and inhibition of neuropeptide release within the trigeminovascular system.
Common triptans include sumatriptan, zolmitriptan, naratriptan, eletriptan, and frovatriptan. Triptans are most effective when taken at headache onset rather than during aura. The onset of action is typically within 30-to-60 minutes. If symptoms recur, a second dose may be taken after two hours, up to a maximum of two doses in 24 hours.
If one triptan is ineffective, an alternative agent or formulation may be tried, as individual responses vary.
Triptans are contraindicated in patients with ischaemic heart disease, cerebrovascular disease, or uncontrolled hypertension. Common adverse effects include flushing, chest tightness, dizziness, and fatigue, which are usually transient.
Antiemetics
Antiemetics, such as metoclopramide, chlorpromazine, prochlorperazine, and domperidone, play an important role in acute migraine treatment. They reduce nausea and vomiting associated with migraine. In addition, metoclopramide is a prokinetic agent which improves
Unlike acute treatments, preventive medications are used regularly to modify the underlying disease process
gastric motility and may enhance the absorption of oral medications.
Gastric stasis, or delayed gastric emptying, may occur during migraine attacks and can delay the absorption and onset of oral medications. For this reason, antiemetics may be considered even in the absence of significant nausea in order to optimise the efficacy of other acute oral treatments.
Clinical considerations in acute management
Excessive use of acute migraine treatments can lead to medication overuse headache. This is characterised by an increase in headache frequency and reduced responsiveness to therapy. It commonly occurs when analgesics or triptans are used on more than 10-to-15 days a month.
Opioids carry a high risk of inducing medication overuse headache and should be avoided in migraine management. Patients should be counselled to limit acute medication use to two days a week or fewer, and to seek medical review if headaches become more frequent or unresponsive to treatment.
Drug absorption may be significantly reduced in the presence of nausea and vomiting. Alternative formulations ? such as nasal sprays, subcutaneous injections, and rectal suppositories ? may therefore be considered to provide a more rapid onset of action and improve treatment efficacy.
Menstrual migraine is characterised by a migraine attack that occurs between two days before and three days after menstruation. These attacks may be severe, long-lasting, and less responsive to standard acute therapy. Triptans are the cornerstone of menstrual migraine management, with agents such as naratriptan and frovatriptan often preferred due to their prolonged half-life. They may be taken perimenstrually for short-term prophylaxis. NSAIDs may also be used during the perimenstrual period, either as monotherapy or in combination with triptans.
Preventive management
Preventive therapy aims to reduce the frequency, severity, and duration of migraine attacks, thereby improving patient quality of life. Unlike acute treatments, preventive medications are used regularly to modify the underlying disease process. Preventive therapy should be considered when patients experience four or more migraine days a month, when attacks are prolonged or disabling, when attacks are inadequately controlled with acute treatment, or when acute medication is contraindicated or overused. Several medications traditionally used for other conditions have demonstrated efficacy in migraine prevention. Selection is guided by comorbidities, adverse effect profile, and patient preference.
Regular monitoring and review of preventive management are essential. Treatment should be reviewed after eight to 12 weeks to assess response, with a meaningful response often defined as at least a 50 per cent reduction in migraine frequency or severity. If effective, treatment is typically continued for six to 12 months before considering gradual withdrawal. If a preventive option fails or is not tolerated, an alternative should be considered.
Propranolol is one of the most widely used preventive options. It is particularly useful in patients with coexisting anxiety or essential tremor. Common adverse effects may include fatigue, dizziness, hypotension, and bradycardia.
Topiramate is an anticonvulsant medication that is effective in reducing migraine frequency. It may be particularly useful in patients with comorbid obesity, as weight loss can occur. Topiramate requires gradual dose titration. Cognitive slowing, paraesthesia, and loss of appetite are adverse effects that may limit tolerability. Topiramate is contraindicated in pregnancy due to teratogenic risk.
Amitriptyline is a tricyclic antidepressant that is an important option for migraine prophylaxis, particularly where insomnia or coexisting tension-type headache features are present. The dose should be gradually titrated, with common adverse effects including sedation, weight gain, and constipation.
Candesartan, an angiotensin receptor blocker, may be used as preventive therapy when other options are ineffective or poorly tolerated. It is particularly useful in patients with comorbid hypertension. Monitoring of blood pressure and renal function is required.
CGRP monoclonal antibodies represent a major advancement in preventive migraine management. These agents target CGRP or its receptor, disrupting a key pathway in migraine pathogenesis. Examples include erenumab, fremanezumab, and galcanezumab. These agents are administered by subcutaneous injection monthly or quarterly, depending on the specific agent. They are generally initiated in specialist settings and may be considered in patients with chronic migraine who have failed multiple preventive therapies.
Clinical benefit is usually observed within weeks. Treatment response should be assessed after 12 weeks and discontinued if no meaningful improvement is observed. They are generally well tolerated, with injection- site reactions and gastrointestinal symptoms being the most common adverse effects.
Gepants are a class of oral CGRP receptor antagonists that have emerged as effective options for both acute and preventive migraine management. They offer an alternative for patients who cannot tolerate traditional preventive therapies or who prefer oral therapy to injectable monoclonal antibodies. Rimegepant can be used for the acute treatment of migraine to provide relief of pain and associated symptoms, while it may also be taken on alternate days for prevention. Atogepant is licensed for once-daily dosing in preventive therapy.
Gepants are generally well tolerated, with nausea and somnolence being the most common adverse effects. These agents represent an important development in migraine therapy and expand the range of available preventive and acute treatment options.
Non-pharmacological management Non-pharmacological strategies play an important role in migraine management and can be combined with pharmacological therapies. These interventions can help reduce attack frequency, improve response to medication, and enhance overall quality of life.
Self-care strategies can play an important supportive role in migraine management. Resting in a quiet, dark environment can reduce photophobia and phonophobia, while cold compresses applied to the forehead or neck may also provide symptomatic relief. Identifying and avoiding common triggers ?such as irregular meals, sleep disturbances, dehydration, alcohol, or stress ? can reduce the severity
or frequency of attacks. A headache diary can help track patterns, recording headache frequency, severity, associated symptoms, potential triggers, and response to treatment.
Patients should be encouraged to maintain regular sleep patterns, consistent meals, adequate hydration, and physical activity. Relaxation exercises and cognitive behavioural therapy may be beneficial in some patients, particularly when stress is a contributing factor. Riboflavin 400mg once daily may help reduce migraine frequency and severity in certain patients. Acupuncture may be considered if preventive therapy fails or is contraindicated. Intramuscular injections of botulinum toxin type A may be considered for chronic migraine prevention if at least three preventive medications have failed or are not tolerated.
Role of the pharmacist
Pharmacists play a crucial role in the management of migraine. Pharmacists are among the most accessible healthcare professionals and are often the first point of contact for patients. They can help distinguish migraine from other headache types, ensuring patients receive appropriate treatment and timely referral when necessary.
Pharmacists contribute to rational analgesic use by counselling patients on the safe and effective use of over- the-counter options such as ibuprofen, paracetamol, and sumatriptan, now available without prescription in Ireland. This involves counselling on dosage, duration of use, and strategies to minimise the risk of medication overuse headache, as well as highlighting the importance of avoiding opioid-containing products for acute migraine management.
Patient education and lifestyle support are essential components of pharmacist- led care. Pharmacists can advise on trigger avoidance, maintaining regular sleep patterns, consistent meals, and adequate hydration. They also ensure the safe and effective use of prescribed medications, including checking for potential drug interactions, monitoring adverse effects, and promoting medication adherence.
Through patient counselling, follow-up, and collaboration with other healthcare professionals, pharmacists are integral to improving migraine outcomes, minimising harm, and enhancing quality of life for patients.
References upon request
