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Contents: (Full
text available in print edition.)
- Penciclovir Cream – A New Treatment for Herpes Labialis
- Human Skin Equivalent (HSE), Apligraf®, Part II: Clinical Use
- Medicated Shampoos are Effective in Many Scalp Conditions
- Update on Drugs
- Tazarotene Gel 0.05%, 0.1%, Tazorac® topical gel
– Allergan
- Podofilox gel 0.5%, Condylox® – Oclassen
- Ketoconazole Shampoo 2%, Nizoral® – Janssen
- Fluticasone proprionate, Cutivate® Cream 0.05% – Glaxo Wellcome
- Amoxicillin/clavulanic acid, Augmentin® – SmithKline Beecham
- Indinavir, Crixivan® – Merck;
Nelfinavir, Viracept® – Agouron; Ritonavir, Norvir® – Abbott;
Saquinavir, Invirase® – Roche
- Acitretin, Soriatane®, Neotigason® – Roche
Human Skin Equivalent (HSE)
Apligraf®
Part II Clinical Use |
 |
| Preparation
of the wound bed, proper application of Apligraf, and patient compliance with underlying
therapy for underlying disease are probably the most important determinants of clinical
efficacy.1,2 |
What are the most important things to remember
about preparing the wound?1
| 1. |
Debride the wound bed so that it is as clean and free of
fibrotic/necrotic tissue as possible. |
| 2. |
After debridement, cleanse the wound bed of debris by
irrigating with a sterile, non-cytotoxic saline solution. You may apply gentle pressure to
stop bleeding and/or use topical hemostatic agents prior to application. |
| 3. |
Contain bacterial infection. |
| 4. |
Control leg edema and heavy wound exudation with elevation
and compression of the leg. |
| 5. |
Implement appropriate therapies for underlying venous
insufficiency. |
Should antimicrobial agents be used prior to the procedure?
The commensals in venous leg ulcers are generally not associated with the kind of frank
infection that would preclude the application of HSE. If necessary, oral, topical or
injectable antimicrobial agents may be used for one week prior to application.1,2 Several commonly
used burn wound antimicrobial agents (including mafenide acetate, polymyxin B sulfate,
nystatin and sodium hypochlorite) may have a deleterious effect on HSE. Certain cytotoxic
agents (Dakin's solution, mafenide acetate, Scarlet Red dressing, tincoban, zinc sulfate,
povidone iodine solution and chlorhexidine) can destroy cellular components of skin and
HSE, and following their use, the wound should be thoroughly cleansed with physiological
saline before application.1
Use of Apligraf1
| 1. |
Apligraf is intended for single-use only. It should
be kept on its tray on the medium in an incubator (19-31°C) until ready for use. It
remains viable for up to five days from the moment it is sealed in the pouch. |
| 2. |
Before opening the plastic container, check the pH of the
mediumby comparing the colour to the colours on the chart provided. The medium is
compromised if the colour is purple, and possibly contaminated if the colour is yellow. |
| 3. |
Handle the Apligraf as little as possible, and use
sterile technique. |
| 4. |
Do not allow the HSE to dry out after opening the package,
and place it on the wound bed within 30 minutes. |
| 5. |
The dermal layer (the glossy layer closest to the medium
in the container) should be placed flush with the wound surface. The epidermal layer
(matte, dull finish) should be facing up, exposed to the air. Express any trapped air.1 HSE must be trimmed to fit inside the
edge of the ulcer margins. |
| 6. |
If exudateis a problem, slits (pie-crusting) with a
scalpel blade, punch biopsies or shredding may help prevent the HSE from floating off the
surface of the wound. To prevent contamination, the holes should be made after HSE has
been removed from the media well.2 |
| 7. |
It is very important to immobilize the HSE in contact
with the wound bed. If securing of the HSE is not complete, staples, sutures or other
methods should be used to prevent shear or friction.2
For venous leg ulcers, cover the HSE with a nonadherent primary dressing (e.g. Tegapore®
or Mepitel®), then apply a pressure bolster (rolled or folded gauze or a foam plug) and
cover the bolster with an elastic wrap/compression bandage.1 |
| 8. |
Within one week of application, HSE may appear translucent
and cellophane-like. The graft may degrade partially or completely following the initial
application. Degraded HSE may appear yellow and gelatinous, and its similarity to
purulent exudate may lead to inappropriate diagnosis of skin infection. In acute or
fresh wounds, HSE appears pinkish or whitish-opaque within 1-2 weeks.1 |
| 9. |
In most cases, one to two applications of HSE will be
sufficient; in a minority of patients, three applications may be necessary. Reapply
within six to eight weeks if less than 50% of the original wound area has closed, or if
the HSE has not completely adhered to the wound. Do not disrupt healing tissue or adherent
HSE, but gently remove nonadherent remnants of the product.1 |
|
| In a number of patients, a single application of HSE has converted
chronic or non-healing wounds to acute, more responsive wounds. Following the initial
application, it may be advisable to wait 8-12 weeks before using a second HSE in order to
determine whether or not wound healing has been jump-started and to prevent unnecessary
expense.3 |
| Dr Gary Sibbald, Toronto |
|
| 10. |
The primary dressing covering the HSE should be inspected and
changed at least once a week. Highly exudative wounds may require more frequent changes.1 |
Information for Patients
|
Patients should be told to expect some scarring but,
generally a return of skin colour and a good cosmetic outcome.4 |
Venous leg ulcer patients should elevate their feet as much as possible for the
first week after application and the underlying venous disease managed aggressively to
prevent recurrence. After the ulcer has healed, they should wear elastic compression
stockings delivering 30-40 mm Hg of pressure and have follow-up inspections every three
months for one year. It is also important that they maintain proper nutrition.1
| One of the most exciting benefits of HSE therapy is its ability to
dramatically accelerate wound closure, up to two to three times faster than conventional
multilayer compression therapy. In the pivotal leg ulcer study, HSE closed as many wounds
by eight weeks as conventional therapy did by six months and also resulted in a
significantly greater number of patients with 100% wound closure. These differences were
even more striking with particulary difficult to heal ulcers (larger or of longer
duration). |
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References
- Data on file, Novartis Pharma AG.
- Falanga V, Margolis D, Alvarez O et al. Rapid
healing of venous ulcers and lack of rejection with an allogeneic cultured Human Skin
Equivalent. Submitted for publication.
- Sibbald G. Personal communication. July, 1997.
- Sabolinski ML, Alvarez O, Auletta M et al.
Cultured skin as a 'smart material' for healing wounds: experience in venous ulcers. Biomaterials1996;
17: 311-320.
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| Class |
Name/Company |
Approval Dates and Comments |
| Anti-acne &
antipsoriatic |
Tazarotene Gel
0.05%, 0.1%
Tazorac® topical gel
Allergan |
Approved by the FDA June 13, 1997 for the topical treatment
of patients with stable plaque psoriasis of up to 20% body involvement, or facial acne
vulgaris of mild to moderate severity. Previously approved in Germany and Canada.
(Reviewed in Volume 2, Number 4, Pages 1-2.) |
| Class |
Name/Company |
Drug Warning |
| Anti-HIV |
Indinavir
Crixivan®
Merck |
Prescribing information is to be updated, US and worldwide,
to include warnings about the possibility of patients developing hemolytic anemia.
According to Merck, 20 cases have been reported in 140,000 patients and no causal link has
been established, but this warning is appropriate as the condition needs to be recognized
and treated quickly. |
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