Hypotension, orthostatic

The most studied component of blood pressure disturbances in the elderly is by far, high blood pressure. Only a very few scientific experiments have been performed on low blood pressure in the elderly. This is, among other reasons, due to the 

Orthostatic reactions is defined as a symptomatic fall in blood pressure and it is measured by a fall in systolic blood pressure by 20 mmHg or to below 90 after three minutes of standing up after lying down (The Consensus Committee 1996). Orthostatic hypotension is estimated to prevail in 18-28% of the population over 65 and in public health surveys as many as 25% of persons over 80 years experienced symptoms related to low blood pressure and orthostatic reactions (Colledge et al. 1994, Brignole 1998). 

Different causes are seen for this condition, including low blood volume (due to, for example, dehydration, overuse of diuretics, anaemia or bleeding), relocation of the blood volume (varicose veins, postprandial symptoms), heart failure, long term immobilisation or drugs (diuretics, antihypertensives, antipsychotics). 

Many different drug classes have shown to cause hypotension and orthostatic reactions and drugs for cardiovascular conditions, psychoactive medicines and polypharmacy, can all have this side effect (Box 5.15). Among the most frequently used drugs in the elderly are diuretics, ACE-inhibitors, angiotensin II antagonists, calcium channel blockers and antidepressants. 

Heart medication, betablockers, ACE-inhibitors, long acting nitro derivates, calcium channel blockers, angiotensin II antagonists 

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Normally, dietary tyramine is broken down in the gastrointestinal tract by MAO and is not absorbed. In the presence of MAOI, however, all of its potent sympathomimetic actions are seen. Other side effects of MAOI include excessive CNS stimulation, orthostatic hypotension, weight gain, and in rare cases hepatotoxicity. Because the monoamine oxidase inhibitors exhibit greater toxicity, yet no greater therapeutic response than other, newer agents, clinical use has been markedly curtailed. The primary use for MAOIs is in the treatment of atypical depressions, eg, those associated with increased appetite, phobic anxiety, hypersomnolence, and fatigues, but not melancholia (2). 

Agent or class CNS effects Orthostatic hypotension Arrhythmias Anticholinergic effects Weight change... 

Nifedipine, verapamil, and diltiazem are all efficacious in the treatment of mild and moderate hypertension, but nifedipine is more efficacious than diltiazem and verapamil in the control of severe hypertension. Nifedipine does not cause significant reflex tachycardia or orthostatic hypotension. Nifedipine benefits the older and black patients and patients with low PRA. 

The acute adverse effects of the organic nitrates as well as molsidomine are directly related to their therapeutic vasodilation as they can cause orthostatic hypotension, tachycardia and throbbing headache. 

However, it is also the major reason for the adverse side effects of ACE inhibitors, namely cough and angio-oedema. Another observed side effect, first-dose orthostatic hypotension, is probably due to both angiotensin inhibition and kinin potentiation. 

Adverse reactions of amantadine include gastrointestinal upset with nausea and vomiting, anorexia, asthenia (weakness, loss of strength), constipation, depression, visual disturbances, psychosis, urinary retention, and orthostatic hypotension. 

Cardiovascular-peripheral vasodilation,decreased peripheral resistance, inhibition of baroreceptors (pressure receptors located in the aortic arch and carotid sinus that regulate blood pressure), orthostatic hypotension and fainting... 

RISK FDR INJURY. Narcotics may produce orthostatic hypotension, which in turn results in dizziness. The nurse should assist the patient with ambulatory activities and with rising slowly from a sitting or lying position. Miosis (pinpoint pupils) may occur with the administration of some narcotics and is most pronounced with morphine, hydro mo rpho ne, and hydrochlorides of opium alkaloids. Miosis decreases the ability to see in dim light. The nurse keeps the room well lit during daytime hours and advises the patient to seek assistance when getting out of bed at night. 

In patients taking midodrine for orthostatic hypotension, the nurse checks the blood pressure with the patient supine and sitting before therapy is begun. This is important because midodrine is contraindicated in patients with supine hypertension. 

The following isa suggested dosing schedule for the administration of midodrine shortly before arising in the morning, midday, and late afternoon (not after 6 00 fm). The nurse should continue drug therapy only in the patient whose orthostatic hypotension improves during the initial treatment. 

EDUCATING THE PATIENT PRESCRIBED MIDODRINE When midodrine is given to patients with severe orthostatic hypotension, tiie nurse explains the importance of... 

Administration of an a-adrenergic blocking drug may result in weakness, orthostatic hypotension, cardiac arrhythmias, hypotension, and tachycardia... 

Q Risk for Injury related to vertigo, dizziness, weakness, and syncope secondary to orthostatic hypotension... 

Symptoms of postural or orthostatic hypotension often lessen with time, and tire patient may be allowed to get out of bed or chair slowly without assistance The nurse must exercise good judgment in this matter. Allowing tire patient to rise from a lying or sitting position without help is done only when tire determination has been made that tire symptoms have lessened and ambulation poses no danger of falling. 

The most common serious adverse reactions to amantadine are orthostatic hypotension, depression, congestive heart failure, psychosis, urinary retention, convulsions, leukopenia, and neutropenia Less serious reactions include hallucinations, confusion, anxiety, anorexia, nausea, and constipation. Adverse reactions with selegiline include nausea, hallucinations, confusion, depression, loss of balance, and dizziness. 

The adverse reactions most often associated with the administration of the COMT inhibitors include disorientation, confusion, light-headedness, dizziness, dyskinesias, hyperkinesias, nausea, vomiting, hallucinations, and fever. Other adverse reactions are orthostatic hypotension, sleep disorders, excessive dreaming, somnolence, and muscle cramps. A serious and possibly fatal adverse reaction that can occur with the administration of tolcapone is liver failure... 

Risk for Injury related to parkinsonism, adverse drug reactions (dizziness, light-headedness, orthostatic hypotension, loss of balance)... 

Inform patients diat orthostatic hypotension may develop witii or witiiout symptoms of dizziness, nausea, fainting, and sweating. Caution die patient against rising rapidly after sitting or lying down. 

Sedation and dry mouth are the most common adverse reactions seen with the use of TCAs. Tolerance to these effects develops with continued use. Orthostatic hypotension can occur with the administration of the TCAs. Orthostatic hypotension is a drop in blood pressure of 20 to 30 points when a person changes position, such as going from a lying position to a standing position. Mental confusion, lethargy, disorientation, rash, nausea, vomiting, constipation, urinary retention, visual disturbances, photosensitivity, and nasal congestion also may be seen. Sexual dysfunction may occur with administration of clomipramine. 

Orthostatic hypotension is a common adverse reaction seen with the administration of the MAOIs. Other common adverse reactions include dizziness, vertigo, nausea, constipation, dry mouth, diarrhea, headache, and overactivity. 

Sedation, anticholinergic effects (dry mouth, dry eyes, urinary retention), nausea, nasal congestion, blurred vision, orthostatic hypotension, lethargy, confusion, constipation, diarrhea... 

Some adverse reactions, such as dry mouth, episodes of orthostatic hypotension, and drowsiness, may need to be tolerated because drug therapy must continue. Nursing interventions to relieve some of these reactions may include offering frequent sips of water, assisting the patient out of the bed or chair, and supervising all ambulatory activities. 

With orthostatic hypotension, the nurse instructs the patient to rise from a lying position to a sitting position. The patient remains in a sitting position for a few minutes before rising to a standing position. Position changes... 

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