Download Phentermine hydrochloride

Phentermine
hydrochloride
(F EN-ter-m een)
CLASSIFICATION(S):
Anorexiant
PREGNANCY CATEGORY: C
Rx: Adipex-P, Ionamin, C-IV
USES
Short-term (few weeks) treatment for
weight reduction with exercise, behavioral modification, and caloric restriction in the management of exogenous
obesity in clients with an initial body
mass of 30 kg/m2 or more or 27 mg/m2
or more in the presence of other risk
factors (e.g., hypertension, diabetes,
hyperlipidemia).
ACTION/KINETICS
Action
Phentermine is a sympathomimetic
amine with similar actions as amphetamine, including increase in BP and
CNS stimulation. Tachyphylaxis and tolerance can occur.
CONTRAINDICATIONS
Advanced arteriosclerosis, CV disease,
moderate to severe hypertension, hyperthyroidism, glaucoma, or known hypersensitivity to sympathomimetic
amines. Also, agitated states, those with
a history of drug abuse, during or within 14 days following the administration
of MAO inhibitors (hypertensive crisis
may occur). Use with other drugs for
weight loss, as well as with selective
serotonin reuptake inhibitors is not recommended. Lactation. Use in children
less than 16 years of age.
SPECIAL CONCERNS
• Abuse of phentermine and development of intense psychological dependence and severe social dysfunction are possible.
• Abrupt discontinuation following
high doses results in extreme fatigue
and mental depression.
• Use with caution even in those with
mild hypertension.
• Insulin requirements in diabetes mellitus may be altered.
C = see color insert
H = Herbal
• Safety and efficacy not determined in
children.
SIDE EFFECTS
Most Common
Dizziness, constipation, dry mouth,
headache, false sense of well being,
N&V, nervousness, insomnia, tremors.
CNS: Overstimulation, restlessness, nervousness, dizziness, insomnia, euphoria,
dysphoria, tremor, headache, exaggerated feelings of depression or elation,
false sense of well being, psychotic episodes (rare). GI: Dry mouth, unpleasant
taste, diarrhea, constipation, GI disturbances. CV: Palpitation, tachycardia,
throbbing heartbeat, increased BP, primary pulmonary hypertension, regurgitant cardiac valvular disease. Miscellaneous:
Urticaria,
impotence,
changes in libido, tremors.
OD OVERDOSE MANAGEMENT
Symptoms: Acute overdose: CNS: Restlessness, tremor, hyperreflexia, rapid
respiration, confusion, assaultiveness,
hallucinations, panic states. Fatigue and
depression follow the central stimulation. CV: Arrhythmias, hypertension or
hypotension, circulatory collapse. GI:
N&V, diarrhea, abdominal cramps. Fatal
poisoning usually terminates in convulsions and coma.
Chronic intoxication: Severe dermatoses, marked insomnia, irritability, hyperactivity, personality changes, psychosis
(indistinguishable
from
schizophrenia).
Treatment: Acute overdose:
• Largely symptomatic.
• Gastric lavage.
• Sedation with a barbiturate.
• Acidification of the urine (increases
phentermine excretion).
• Phentolamine, IV for acute, severe
hypertension.
DRUG INTERACTIONS
Alcohol / Adverse drug reaction possible
Dexfenfluramine / Possible primary pulmonary hypertension (rare); also, possible serious regurgitant cardiac valvular
disease (primarily affecting the mitral,
aortic, and/or tricuspid valves)
Fenfluramine / Possible primary pulmonary hypertension (rare); also, possible
serious regurgitant cardiac valvular disease (primarily affecting the mitral, aorIV = Intravenous
E = sound alike drug
tic, and/or tricuspid valves)
Guanethidine /앗 Guanethidine hypotensive effect
MAO inhibitors / Possible significant 앖
BP; do not use together. Allow at least 2
weeks to elapse between the use of an
MAOI and phentermine
HOW SUPPLIED
Capsules: 18.75 mg, 30 mg, 37.5 mg;
Capsules (resin): 15 mg, 30 mg; Tablets: 8
mg, 37.5 mg.
DOSAGE
• CAPSULES; TABLETS
Exogenous obesity.
Adipex-P: One capsule or tablet (37.5
mg) once daily, given before breakfast
1
or 1–2 hr after breakfast. For some, /2
tablet (i.e., 18.75 mg) daily may be ade1
quate. Or, for some, give /2 tablet two
times/day. Ionamin: One capsule or
tablet (various doses) once daily, given
before breakfast or 2 hr after breakfast.
1
For some, /2 tablet may be adequate
Take capsules 10–14 hr before bedtime.
NURSING CONSIDERATIONS
ADMINISTRATION/STORAGE
1. Tolerance to the anorectic effect
usually occurs within a few weeks. Do
not exceed the recommended dose in
an attempt to increase the effect; rather, discontinue the drug.
2. Store at room temperature.
ASSESSMENT
1. List reasons for therapy, risk factors,
BMI, other agents trialed, outcome.
2. List medical conditions that may require weight loss. Identify those that
preclude therapy: advanced arteriosclerosis/CAD, hyperthyroidism, glaucoma,
drug abuse history, extreme agitation.
Bold Italic = life threatening side effect
3. Monitor VS, renal and LFTs, BMI. Assess for tolerance, anorectic effect usually develops within a few weeks.
CLIENT/FAMILY TEACHING
1. Take only as directed. Avoid late evening administration due to the possibility of insomnia. Swallow Ionamin capsules whole.
2. If a dose is missed, skip the missed
dose completely; take the next dose at
the regularly scheduled time. Continue
to remain in and follow medically supervised weight loss program.
3. Do not perform activities that require mental alertness until drug effects
realized; may experience cognitive
impairment.
4. Continue calorie restrictions and regular daily exercise to ensure weight loss.
5. Drug may cause pulmonary hypertension which is fatal. Shortness of
breath is the first symptom but other
symptoms include: chest pain (angina
pectoris), syncope, or lower extremity
edema. Report immediately any S&S or
deterioration in exercise tolerance and
stop therapy.
6. Drug may cause psychological dependence and social isolation. Do not
increase dose and do not stop abruptly
after prolonged therapy. Severe side effects may occur. Store safely out of the
reach of children.
7. Monitor FS. Insulin requirements
may be altered with the use of Ionamin
and the recommended dietary regimen.
8. With hypertension, monitor BP closely. Drug may cause significant increases
in BP.
9. Keep all F/U to assess response, VS,
labs, and for adverse SE.
OUTCOMES/EVALUATE
Desired weight loss
■ = black box warning
W = Available in Canada