US Pharm
. 2012;37(1):30-33. 

Dizziness is a nonspecific term used by patients to describe a sensation of altered spatial orientation. It encompasses a wide range of symptoms that vary from violent, spinning vertigo to vague symptoms of unsteadiness, lightheadedness, imbalance, disorientation, incoordination, and clumsiness. Vertigo is medically defined as an illusion of movement, or any abnormal sensation of motion between a patient and his or her surroundings.1-3 Dizziness is a common complaint among patients, particularly in the elderly, and is often difficult to describe. Thus, it is important to understand the etiology of dizziness and vertigo in order to properly evaluate and manage patients. 

Prevalence

Dizziness is the third most common complaint among outpatients.4 An estimated 5 out of 1,000 people consult their primary care physician annually for vertigo, and 10 out of 1,000 for dizziness.2 In 80% of these cases, the effects of dizziness are severe enough to necessitate medical intervention,5 though causes remain unexplained 40% to 80% of the time.6 Dizziness affects >50% of the elderly population and is the most common reason for physician visits among patients >75 years of age.5 Less than half of patients who experience dizziness have true vertigo.1 Chronic dizziness and vertigo can result in loss of function, falls, and injuries that can lead to nursing home placement, stroke, and death.7,8 

Diagnosis

Assessment of a patient with complaints of dizziness requires a thorough history and physical examination in order to determine the actual issue. It is also important to note the onset, duration, number of episodes, triggers, and any associated auditory and neurologic signs.1,3,7,9 Common causes of dizziness include benign paroxysmal positional vertigo (BPPV), fear of falling, migraines, sensitivity to motion, and vestibular loss.5 

Due to the generality of the term dizziness, the classification of this condition has been proposed. The first type involves an illusion of movement, also described as a spinning sensation and termed vertigo. The second type is a presyncopal episode, or the feeling of imminent fainting or loss of consciousness. The third type is disequilibrium, or impaired balance and gait. The fourth type is lightheadedness, which is an indistinct term used to describe symptoms that do not fit the other categories. It may be described as feeling disconnected from the environment. If dizziness is not due to vertigo, other medical conditions (e.g., cardiac arrhythmia, diabetes, thyroid disorder) should be investigated.9-11 

Patient History: A common feature of true vertigo is a spinning sensation that may present as objective (patients complain of objects moving around them) or subjective vertigo (patients feel they are spinning). If vertigo is suspected, it is important to determine whether the cause is central or peripheral (TABLE 1). Central vertigo is commonly due to migraines, cerebrovascular disease, or cerebellopontine angle tumors. Peripheral vertigo occurs more frequently and is primarily due to infection, inflammation, and/or stimulation of various auditory nerves and organs. Typical features of peripheral vertigo include a short or episodic time course, a precipitating factor, and the presence of autonomic symptoms (e.g., sweating, pallor, nausea, or vomiting). It may also be associated with tinnitus, hearing loss, auditory fullness, or facial nerve weakness. In central vertigo, autonomic symptoms are less severe and hearing loss is uncommon. It has a gradual onset and is associated with neurologic symptoms such as visual changes (e.g., diplopia, hemianopsia), weakness, numbness, dysarthria, ataxia, and loss of consciousness.3,7,12

A comprehensive review of a patient’s medication history should be performed to determine whether therapy must be altered. The administration of certain drugs (e.g., acetyl-salicylic acid, amiodarone, cisplatin, ethacrynic acid, furosemide, gentamicin, quinine, streptomycin, tobramycin) may result in direct ototoxicity and should be discontinued in patients experiencing vertigo. Psychotropic agents, antihypertensives, anti-inflammatory agents, and muscle relaxants are also reported to cause lightheadedness and disequilibrium in patients (TABLE 2).5,7 A number of these drugs can cause orthostatic hypotension, which may manifest as dizziness.11 Symptoms of dizziness usually resolve after cessation of the offending agent. However, consequences such as vestibular and cochlear damage may result in permanent ataxia or hearing loss. Patients who chronically use vestibular suppressants (e.g., meclizine, scopolamine) may become sensitized to these drugs and experience withdrawal symptoms when they are discontinued.3,5,7 

Social history should be evaluated, as many factors can precipitate or worsen dizziness and vertigo (e.g., alcohol, nicotine, caffeine). Current or prior history of illicit drug use, sexual history (e.g., syphilis, herpes), traumatic head injury, cervical trauma, depression, anxiety, and other conditions (e.g., blood pressure alterations, arrhythmias, hypoglycemia, dehydration) should be noted since all can manifest dizziness.3,7,11

Physical Examination: A complete physical examination includes ocular, otologic, cardiac, and neurologic components. In the ocular examination, papillary reactivity and extraocular movements are tested because abnormalities can suggest cerebellar disease. Patients with nystagmus should be assessed and family members asked if any unusual eye movements have been noted during a vertiginous event. Patients with peripheral vestibular disease could suppress the nystagmus by focusing on a stationary target. The inability to do so suggests a central problem. Head thrusts and positional testing may also be performed to check for the vestibulo-ocular reflex in which eye movements are observed to determine whether nystagmus is present and vestibulo-ocular reflexes are intact.1,3,5,7,11 

Otologic examinations evaluate for the presence of impacted cerumen or other foreign objects in the ear canal, which may require removal for relief of vertiginous symptoms. Signs of middle ear disease (e.g., fluid behind the eardrum, perforation, extensive scarring, hearing loss) should be further evaluated.7 

The patient’s blood pressure should also be taken—once in a supine position and then a minute later upon standing. If the systolic blood pressure decreases by 20 mm Hg, diastolic blood pressure decreases by 10 mm Hg, or pulse increases by 30 beats per minute (bpm), the patient may have orthostatic hypotension.11 Auscultation of heart and carotid arteries could reveal other vascular causes of dizziness. Findings of a carotid bruit, heart murmur, or irregular rhythm should be followed by a thorough cardiovascular workup, particularly in elderly patients.7 

A neurologic examination is vital and should include a complete cranial nerve evaluation to help identify localized lesions in the brain. Finger-to-nose pointing and rapidly alternating movements are used to assess cerebellar function. The Romberg’s test involves balance and requires the patient to stand with feet together and arms folded (with a practitioner standing behind the patient). The inability to maintain this position by swaying or falling suggests vestibular dysfunction. Gait abnormality is usually indicative of a central lesion. Ataxic gait associated with cerebellar disease is characterized by slowness, wide base, unsteadiness, step irregularity, tremor of the trunk, and side-to-side lurching.7,11 

Lightheadedness may be caused by a hyperventilation syndrome where a patient inhales and exhales faster than the body can accommodate, resulting in respiratory alkalosis. Diagnosis can be attested by having the patient rapidly inhale and exhale deeply 20 times, which simulates the symptoms.11 

Other Tests: Most routine laboratory tests are not helpful in assessing vertiginous symptoms. However, a complete blood and chemistry panel can be useful in patients without clinical findings or with near syncope. An electrocardiogram (ECG) should be obtained in older adults and those with significant or troubling cardiac risk factors. If arrhythmia is suspected, a 24- to 48-hour continuous ECG could help determine whether the dizziness is due to an arrhythmia. Electronystagmography (ENG) is a diagnostic test that records eye movements in response to vestibular, visual, cervical, caloric, rotational, and positional stimulation and is helpful in detecting vestibular dysfunction and nystagmus. In this test, electrodes are placed at the outer and inner canthi of the eyes for horizontal readings, as well as above and below the eye for vertical readings.3,7,11 

A CT or MRI of the brain is indicated in patients with suspected cerebellar hemorrhage, cerebellar infarction, or other central lesions. Radiologic imaging should be considered in patients with new-onset vertigo, findings of neurologic abnormalities, or symptoms lasting longer than 2 weeks. MRI, vascular imaging, and cardiac imaging should also be considered in people at risk for stroke. If a patient has an implanted metal device or if there is middle ear pathology, CT of the temporal bones is recommended.3,7 

Pharmacologic Management

Dizziness: In patients without apparent vertiginous symptoms, the distinction of the dizziness complaint remains broad and unclear. Oftentimes, dizziness is a multisensory disorder, affected by peripheral neuropathy, visual impairment, and musculoskeletal disease. Treatment of the underlying cause would relieve the dizziness. Anemia, iron deficiency, malignancy, vitamin deficiency, and chronic blood loss may result in insufficient blood flow to the brain and manifest as lightheadedness. Patients with thyroid dysfunction or hypoglycemia may also present with dizziness. Pregnancy or menstruation may cause lightheadedness due to acute changes in hormone levels.7 

Patients with orthostatic hypotension can be treated with midodrine and fludrocortisone to increase blood pressure; however, blood pressure monitoring is necessary to prevent any consequential complication. Midodrine should not be taken within 4 hours of bedtime or when lying down, as it could cause supine hypertension. Other common side effects include urinary frequency, urinary retention, and skin rash. Fludrocortisone is a mineralocorticoid that increases sodium and water retention. Thus, it is important to monitor potassium levels and for heart failure symptoms. Other common side effects include edema, hyperglycemia, increased risk of infection, and muscle weakness. Pseudoephedrine, paroxetine, and desmopressin are other options when midodrine and fludrocortisones are not effective.5,11,13,14 

Dizziness and vertigo can also present in patients with migraines. Migraines are a vascular disorder that manifest as periodic, unilateral headaches that are often preceded by neurologic symptoms called the aura. Acute migraine attacks can be treated with nonopioid analgesics, antiemetics, nonsteroidal anti-inflammatory drugs, and 5-HT antagonists. Preventative medications for migraines include amitryptyline, beta-blockers, calcium channel blockers, and acetazolamide.2,7 

Psychogenic dizziness can occur in patients with chronic anxiety. Panic attacks are described as sudden intense fear or discomfort and are often associated with dizziness, nausea, shortness of breath, chest tightness, paresthesias, and perspiration. Selective serotonin reuptake inhibitors are frequently used to treat chronic anxiety and panic disorders. Benzodiazepines can also be used for short-term treatment of anxiety.7,11 

Vertigo: Pharmacologic treatment of vertigo depends on the etiology of the condition. However, vestibular suppressants can be used to alleviate vertiginous symptoms. These drugs should only be taken for a short period of time (~1 week) and then be titrated off because of their potential to delay compensation. There are three main categories of vestibular suppressants: anticholinergics, antihistamines, and benzodiazepines. Anticholinergics decrease the rate of firing in the vestibular nuclei. Although not indicated for vertigo, glycopyrrolate is less sedating than the other drugs used to treat vertigo.3 Antihistamines, such as meclizine, have anticholinergic effects and are much more sedating than true anticholinergics. Benzodiazepines are effective for vertigo, but they may be habit-forming. For acute cases of severe vertigo, IM promethazine or IV droperidol can be used.2,3,5,7,13,14 

Antiemetics may also be used to help with nausea associated with vertigo. Metoclopramide is a dopamine antagonist that also enhances gastrointestinal (GI) tract motility and accelerates gastric emptying. It has been associated with lightheadedness, drowsiness, headache, GI upset, diarrhea, and muscle weakness. Ondansetron is a serotonin antagonist used to prevent chemotherapy-induced emesis, but it has been used for other types of nausea as well. Side effects include headache, fatigue, malaise, constipation, and dizziness. Prochlorperazine and promethazine are both phenothiazines that affect several neurotransmitters (e.g., histamine, dopamine, norepinephrine, acetylcholine) and produce an antiemetic response. Side effects include dizziness, blurred vision, constipation, dry mouth, and photosensitivity. Prochlorperazine can also cause changes in gait, muscular tremors, and weight gain. The severity of the patient’s nausea and the drug’s side-effect profile will help determine which drug is more appropriate for the patient.2,3,5,7,13,14 

TABLE 3 summarizes drugs that can be used to treat symptoms of dizziness, vertigo, and associated nausea.5,11,13-15

Nonpharmacologic Management

Physical Therapy: In certain cases of dizziness and vertigo, vestibular rehabilitation may be beneficial. These activities help the brain to use certain visual and proprioceptive cues to maintain balance and gait. The Cawthorne-Cooksey exercises involve head and body movements, as well as eye-head coordination and balance tasks. Other customized programs that may improve compliance and outcomes include habituation exercises, balance and gait exercises, and general conditioning. Visual motion desensitization with repeated optokinetic stimulation uses moving visual environments to improve vestibular-ocular response as the brain attempts to stabilize gaze. With visual vertigo, optokinetic stimulation with full-field stimuli uses visual environmental displays in a controlled setting to promote compensation.2,10,15 

Role of the Pharmacist

Dizziness and vertigo may affect patients of all ages and are commonly associated with neurosensory, cardiovascular, and psychiatric conditions, as well as with the use of multiple drugs. These symptoms can be severe enough to affect patients’ daily activities. Pharmacists can contribute to the management of dizziness by reviewing patient medication history and profiles, as well as by inquiring about the patient’s symptoms (e.g., severity, onset, duration, and associated symptoms). Pharmacists can help patients recognize whether dizziness may be more serious than transient discomfort and require further medical attention. After the evaluation and diagnosis of dizziness or vertigo, appropriate treatment plans can be developed. Pharmacists should counsel patients to properly take their medication(s), caution them about potential drug-related adverse effects, and encourage vestibular exercises (when necessary) in order to aid in improving overall quality of life. 

REFERENCES

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13. Lexi-Drugs. Hudson, OH: Lexi-Comp, Inc; 2011.
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