P&T News: May 1995, Vol. 15, No. 11
Jacqueline Pilzer, Pharm.D., and Mary B. Ross, R.Ph.,
M.B.A.
Peer Review Status: Internally Peer Reviewed by Michael B.
Edmond. M.D., M.P H., Assistant Professor, Division of General
Medicine, Clinical Epidemiology and Health Services Research,
Department of Internal Medicine
Lice
Head (Pediculus humanus capitis), pubic (Phthirus pubis), and body
(Pedicures humanus corporis) lice are highly contagious and are one
of the most common parasitic infestations causing dermatosis. Itching
is the most common symptom of this infestation. The egg of the louse,
also called the nit, can be seen deposited on the hair 3 to 4 mm from
the scalp. While lice are usually associated with poor hygiene,
overcrowding and unsanitary conditions, this is not always the case;
lice actually affect all socioeconomic groups. Head lice are common
in child care situations and in school-aged children. Transmission
can occur by direct contact with infested individuals or indirectly
by contact with their personal belongings such as combs, brushes, and
hats. Pubic lice infestations are common in adolescents and young
adults and are transmitted though sexual contact. Body lice are
generally found on persons with poor hygiene. 1-3
Permethrin
Permethrin is currently the drug of choice for treating head lice in
adults and children.4 However, the safety and efficacy have not been
established in children less than two months of age.5 Permethrin has
a low potential for toxicity; the most frequent adverse reaction is
pruritus. This symptom may be a manifestation of the parasite itself,
but may also be aggravated following treatment.5 Permethrin has a
high cure rate and high ovicidal activity.2 One study showed that the
cure rate following its application is higher than following the
application of lindane; 99% of patients treated with permethrin were
lice free 14 days after a single application versus 85% for the
lindane-treated patients.6
Permethrin is available as a 1% cream rinse (Nix(R)) for the treatment of lice. The cream rinse should be applied after the hair has been washed with shampoo, rinsed with water and towel dried. An amount of cream rinse sufficient to saturate the hair and scalp is applied and allowed to remain on the hair for 10 minutes before rinsing off with water. A single treatment usually eliminates head lice infestation activity for up to 10 days. If live lice are observed seven days or more after the first application, a second treatment should be given.5 The nits may be removed with the nit comb provided in the package.
Pyrethrins with Piperonyl Butoxide
Pyrethrins with piperonyl butoxide (A-200,(R RID,(R)) R&(~# are
natural pyrethrin compounds derived from certain flowers of the genus
chrysanthemum. Due to possible cross allergenicity, it is suggested
that people hypersensitive to ragweed avoid these products.7
Synthetic piperonyl butoxide is added to block detoxification of the
pyrethrins by the parasite. These products are available as various
nonprescription shampoos, gels or liquids. The selected product
should be applied for 10 minutes after which the area needs to be
rinsed well. ' Although the first treatment is often successful,
ovicidal activity is low and repeat application is advised after 7 to
10 days to kill newly hatched lice.2 When applied appropriately,
toxicity is low and it is usually limited to local irritation.
Lindane
Lindane (Kwell,-(R)gamma benzene hexachloride) has become a
second-line treatment for head and pubic lice due to its potential
toxicity, which is the highest of all pediculocides.2 3 Central
nervous system (CNS) stimulation ranging from dizziness to
convulsions has been reported, but these effects were almost always
associated with accidental oral ingestion or overuse of the product.2
Animal studies indicate that the potential toxic effects are greater
in the young.8 Lindane has also been shown to cause eczematous
eruptions.8 Lindane should be used with caution in young children and
during pregnancy and lactation.3 The use of lindane is
contraindicated in patients with seizure disorders.8
Oil enhances the absorption of lindane; therefore, if the patient uses an oil-based hair dressing, it is recommended that the hair be shampooed and dried before applying lindane shampoo.8 It is very important not to exceed the recommended dosage and duration that the product is in contact with the skin. The health care professional must emphasize this important safety information to the patient.
A 1% lindane shampoo is available for the treatment of lice. Enough shampoo needs to be applied to dry hair to thoroughly wet the hair and the skin of the infested and adjacent areas. The shampoo should remain in place for only 4 minutes. After adding small amounts of water to form a good lather, the hair should be thoroughly rinsed and briskly towel dried. Nits may be removed with a fine toothed comb when the hair is dry. Ovicidal activity is low.2 Evidence of surviving lice seven days after treatment is an indication that an additional treatment is necessary. 8
Other Treatment Considerations
For infestation of eyelashes, petrolatum ophthalmic ointment should
be applied 3 to 4 times per day for 8 to 10 days. Nits should be
mechanically removed using tweezers.
For the eradication of body lice, pediculicides are not necessary. 1-3 Treatment consists of improved hygiene and washing .
To prevent reinfestation, clothing, bedding, and cloth toys can be disinfected by machine washing or drying using hot cycles, since temperatures exceeding 128.3°F for 5 minutes are lethal to lice and eggs.2 Dry cleaning or simply storing clothes in plastic bags for 10 days is also effective. For disinfecting combs and brushes, soaking in hot water for 10 minutes or washing with a pediculicide shampoo is recommended. With all types of hoe, it is important to examine and treat all contacts if necessary
|
Table 1. Drug Treatment Options for Lice and Scabies | |||
|
Product |
Prescription Status |
Application Time |
Adverse Effects/Warnings |
|
LICE |
|
|
|
|
Permethrin 1%* Cream Rinse (Nix[R]) |
OTC |
10 minutes |
Pruritis |
|
Pyrethrins with Piperonyl Butoxide (RID,[R]A-200,[R]R&C,[R]others |
OTC |
10 minutes |
Skin irritation |
|
Lindane 1% Shampoo (Kwell[R], others) |
Rx |
4 minutes |
Central nervous system toxicity, including seizures with overuse Skin irritation |
|
SCABIES |
|
|
|
|
Permethrin 5%* Cream (Elimite[R]) |
Rx |
8 to 14 hours |
Mild tingling, burning |
|
Lindane 1% Lotion or Cream (Kwell[R], others) |
Rx |
8 to 12 hours |
Central nervous system toxicity including seizures with overuse Skin irritation |
|
Crotamiton 10% Cream or Lotion (Eurax[R]) |
Rx |
24 hours, with a second application 24 hours later |
Skin irritation |
|
* Therapy of choice | |||
Scabies
Scabies is a contagious skin infestation caused by the arachnid mite
Saroptes scabies The mite burrows beneath the stratum corneum and is
characterized by intense itching and secondary inflammation. The most
common infestation sites are the interdigital spaces of the fingers,
the flexor surfaces of the wrists, the external male genitalia, the
buttocks and the anterior axillary folds. The head and neck are
usually not affected, except in infants The diagnosis can be made by
identifying the mite under a microscope. The burrow may be visible to
the naked eye and appears as a narrow slightly raised dark line, but
often the burrows are obliterated by scratching long before a patient
is seen by a physician. Scabies is often associated with poor hygiene
and crowded conditions. T he mite Is endemic in many developing
countries. Transmission usually occurs through bodily contact with an
infested host, clothing, or bed linen. ~3
Permethrin
Permethrin 5 % cream (Elimite OR)) is the drug of choice for the
treatment of scabies in infants, children, and pregnant or nursing
women.2 It is not known whether permethrin is excreted in human milk
and consideration should be given to temporarily discontinuing
nursing, should the mother require therapy.9 The cream should be
applied over the entire body below the head. Because scabies can
affect the head, scalp, and neck in infants and young toddlers,
treatment o f the entire body is required for this group.2 After
being massaged into the skin, it must be removed by washing after 8
to 14 hours.
Usually 30 g is sufficient for the average adult. One application is usually curative. Side effects commonly include mild burning, tingling and erythema.9
Lindane
Lindane 1 % lotion and a ream (Kwell ' ) are second-line therapy for
scabies because of toxicity concerns, particularly neurotoxicity.2
They should be used with caution in infants and pregnant women. The
lotion should be applied to the dry skin in a thin layer and rubbed
In thoroughly.10 Lindane should not he used following a bath or by
persons with extensive dermatitis because of concerns of increased
absorption and subsequent seizures.11 If crusted lesions are present,
a tepid bath preceding the medication application is helpful in
loosening them, but it is important to allow the skin to dry before
using the lotion.1,10 Use on open cuts and extensive excoriations
should be avoided as that may also lead to excess systemic absorption
of lindane I Visually. 60 ml is sufficient for an adult. A total body
application from the head down should be made and left on far 8 to 12
hours and then removed by thorough washing. One application is
usually curative. Many patients will exhibit persistent pruritus
after treatment, but this is rarely a sign of treatment failure.
Retreatment is not indicated unless living mites can be
demonstrated.1 Unnecessary skin contact should be avoided in those
applying lindane therapy to others
Crotamiton
Crotamiton 10% cream or lotion (Eurax (R)) can also be used to treat
scabies. However, this therapy is prone to treatment failure. anti
usually requires a second application.1,2 A thin layer is applied
uniformly to all skin surfaces and is left on the skin. A second
application is advisable 24 hours later. The patient should take a
cleansing bath 24 to 48 hours after the last application to
rem()>e any ren ainlng drug. Retreatment may be necessary after 7
to 10 days if mites appear or new lesionsdevelop. Adverse effects may
include allergic sensitivity and skin irritation.1
Other Treatment Considerations
To prevent reinfestation, bedding and clothing should be laundered in
hot water and a hot drying cycle. The parasites do not survive more
than 3 to 4 days without contact with the slain. Clothing that cannot
be laundered should be removed from the patient and stored 101 a week
or more to avoid reintestation.2 Fingernails should be trimmed
because the space 11etw~#:en the fingernail and the skin mar harbor
mites.3
Summary
Permethrin provides a highly effective ant safe treatment for the
management of lice and scabies. Patients should be carefully
counseled regarding: 1) the appropriate application of the respective
products to ensure optimal effectiveness; 2) the potential toxicities
that can occur with misuse and/or overapplication, particularly with
lindane; and 3) the proper measures to take to prevent reinfestation
Patients should also be counseled that pruritus may persist for
several days post treatment and does not necessarily signets a
treatment failure. Requests for refills or frequent purchase of
nonprescription pediculocides should be a cute that additional
patient education is needed.
References
Shortly after sumatriptan (Imitrex(R) ) was approved by the FDA in 1993, reports of cerebrovascular events associated with its use began to appear in the literature. Two such cases are described below.
A 46-year-old man who had a 20-year history of migraine attacks began using sumatriptan. During the first two weeks of therapy, he injected himself with five subcutaneous doses of 6 mg each. A week following his last dose he developed a cerebral infarct and experienced symptoms of hypoasthesia, hemiparesis, and weakness in his right arm and leg. Computed tomography (CT) of the brain demonstrated an area of low attenuation in the left thalamic region. After three months of physiotherapy, the patient was completely recovered and his CT scan returned to normal.
The second case involved a 25-year-old woman who was first diagnosed with migraine during her first pregnancy at the age of 22. A year later, migraine headaches recurred when she began taking oral contraceptives. One month prior to admission, she had again resumed taking oral contraceptive. Migraine headaches again occurred heralded by teichopsia and left-orbital pain, followed by right-sided numbness and throbbing frontal headache. She was given one 6 mg dose of subcutaneous sumatriptan. Twelve hours after the dose, she developed a right hemiparesis (power 3 out of 5); however, her brain CT scan was normal. Her symptoms resolved within one week.
Both of these patients had no identified risk factor for vascular disease.
______
Abstracted from: Lancet. 1993;341:1091-2.
_______
When sumatriptan was first marketed, the manufacturer warned that individuals with underlying heart disease should not use the drug because of its potential to constrict coronary arteries. Post-marketing experience, including incidents similar to those described above, has prompted the manufacturer to revise labeling and include new warnings in the package insert. These additional warnings are:
__________
Source: "Dear Healthcare Professional" Letters. Sumatriptan (Imitrex
L ). Cerenex Pharmaceuticals. Research Triangle Park, NC. August and
November 1994.
Drugs Added to Stock
COLCHICINE Injection: 500 mg/ml, 2 ml ampul Intravenous colchicine is used for the management of acute gouty arthritis attacks. Note: Injectable colchicine was discontinued by the manufacturer, but has recently been reintroduced.
FENTANYL Oral Lozenge: 200 mcg, 300 mcg, 400 mcg Fentanyl oral lozenges (Fentanyl Oralet(R)-Abbott) are indicated for anesthetic premedication in children and adults, and for use in anesthesia or monitored anesthesia care. Note: This product should be administered in monitored settings and by persons specifically trained in the use of anesthetic drugs and the management of the respiratory effects of potent opioids, including maintenance of a patient airway and assisted ventilation. Resuscitative treatments and equipment should be readily available.
HEPATITIS A INACTIVATED VACCINE Injection: 1440 EL.U. per 0.5 ml, pediatric strength Hepatitis A vaccine (Havrix(R)-SKB) is indicated for active immunization of persons 2 years of age against disease caused by hepatitis A virus. Note: The pediatric strength will be stocked as soon as it is commercially available.
IBUPROFEN Tablets: 100 mg Chewable Tablets: 50 mg These pediatric formulations of ibuprofen (Motrin(R)-McNeil) are indicated for the reduction of fever in patients aged 6 months or older and for the management of juvenile arthritis.
Drugs Deleted from Stock
CHLOROQUIN1E PHOSPHATE 250 mg TABLETS Discontinued by all manufacturers. The 500 mg strength is still available.
CLOFAZIMINE 100 mg (LAMPRENE(R) '9-Ciba) CAPSULES Discontinued by the manufacturer. The 50 mg strength is still available.
GLUCAGON 10 mg INJECTION Discontinued by the manufacturer. The 1 mg vial is still available.
POLYTEF PASTE Discontinued due to low use.
SODIUM CITRATE 0.3M SOLUTION This compounded product was deleted due to low use. Commercially available sodium citrate and citric acid solution (Bicitra (R)) is the stocked alternative product.
THEOPHYLLINE 250 mg EXTENDED-RELEASE (SLO PHYLLIN(R) GYROCAPS) CAPSULES Discontinued by the manufacturer. The 125 mg strength is still available.
Product Changes
CROMOLYN Cromolyn 4 % Ophthalmic Solution is again commercially available (Crolom(R)-Bausch & Lamb).
TERAZOSIN All strengths of terazosin (Hytrin(R)) have been reformulated to capsules.