This article is for interest only. No metion of Procept, but does talk about STD (near end of article).
From
U.S. Pharmacist
Proper Use of Vaginal Spermicides
Author: W. Steven Pray, Ph.D., R.Ph., Professor, Pharmaceutics, School of Pharmacy,
Southwestern Oklahoma State University, Weatherford, OK
Abstract: The effectiveness of vaginal contraceptives is
improved by a thorough understanding of how to use them
properly. [U.S. Pharmacist 22(9): 24-37, 1997. c 1997 Jobson
Publishing Corp.]
Introduction
Pharmacists are often called on to provide information about
different methods of contraception. Patients need several types
of information to allow them to make an informed choice,
including failure rates in typical users, relative costs, protection
against sexually transmitted diseases (STDs) and adverse
reactions.
Vaginal spermicides, which use two different mechanisms to
prevent pregnancy, are a viable option for contraception. Their
placement in the vagina produces a barrier to sperm penetration
of the cervical os, and the chemicals in them are directly toxic to
sperm. In contrast to agents that must be taken orally or
implanted in the body, vaginal contraceptives are known as
coitally related or episodic products, in that they only need to be
used when sexual activity is imminent.[1] Thus, females are not
exposed to the agent throughout the month, as they are with the
oral contraceptive, intrauterine device, implanted insert or depot
injection.
In order to be ideal as spermicidal agents, vaginal contraceptives
must meet four criteria:
Act rapidly and effectively, killing all sperm on contact or
rendering them incapable of fertilization
Be systemically nontoxic and nonirri- tating to vaginal and
penile skin and mucosa
Not have any effect on the development of an embryo or
fetus
Be free of long-term toxicities.[2]
While currently available agents have been thought to meet these
four criteria fairly well, they are being examined critically,
especially in regard to their efficacy.
Consumers who understand the proper way to use a vaginal
spermicide may be able to prevent pregnancy. However, used
improperly, their effectiveness is compromised. There is evidence
to suggest that properly informed patients choose spermicides
as a part of a total contraception program. When students in a
human sexuality course were educated appropriately, the
percentage of men who would use a spermicide in addition to a
condom grew from 20% to 32%; in females, the percentage rose
from 15% to 26%.[3] Students also chose to add a spermicide to
a condom to prevent STDs (rather than use a condom alone) in
greater numbers than before they took the course.
Mechanism of Action
Vaginal spermicides are surfactant agents.[4] Surfactants have
been used as contraceptive agents for almost 60 years. They are
thought to act on the midpiece and tail of sperm, directly
affecting the lipid layer, which provides protection to the surface
of sperm.[2] By affecting this vital layer of membranes, they
cause the sperm to lose motility and alter their permeability.
Additionally, sperm must metabolize fructose to maintain full
activity. Surfactants hamper the fructolytic activity of sperm; it is
a lethal change they cannot survive.
Ingredients Available
Surfactants are classified as ionic, cationic or nonionic.[4]
Nonionic sur-factants are most useful for humans. In the United
States, the most commonly used vaginal spermicide is the
neutral agent nonoxynol-9. However, octoxynol is also fully
approved by the FDA. In other parts of the world, the surfactants
benzalkonium chloride (cationic) and docusate sodium (anionic)
are also used for contraception.[4]
Advantages
In surveys of spermicide users, women say they appreciate
spermicidal products because they not only prevent conception,
but improve sexual satisfaction and are convenient to use.
Women also believe that they prevent sexually transmitted
diseases.[5] Male users also list these features and appreciate
the additional lubrication the products provide. Inadequate
lubrication during sexual activity is a major factor causing rupture
of condoms; vaginal spermicides that contribute to vaginal
lubrication reduce risk of pregnancy and STDs.
Adverse Reactions to Vaginal Spermicides
Used according to directions, vaginal spermicides are usually
free of adverse effects. They have been available for over 40
years; the relative paucity of reports is testimony to a low
incidence of adverse reactions. However, several problems are
covered in the medical literature.
Vaginal Irritation. The detergent effect of vaginal
spermicides can produce vaginal irritation.[11] Prostitutes,
who tend to use greater amounts of the product, report
fairly high incidences of both vaginal and oral irritation with
spermicidally lubricated condoms.[9] Vaginal soreness
and irritation of the penis are also possible. At higher
concentrations than those that are available commercially,
vaginal spermicides may produce lesions and ulcerations
of vaginal epithelium.[4,9,12]
It is possible that spermicides will never be able to reduce
the risk of STDs such as HIV in vivo since vaginal and
cervical mucosal damage may actually enhance the risk
of STD transmission.[10] Further, if vaginal irritation
becomes too troublesome, compliance will diminish,
increasing the risk of conception.[13] Fortunately, at
commercially available concentrations, vaginal irritation is
not a common adverse reaction.
Vaginal Infections. Vaginal spermicides can potentially
disrupt the vaginal ecology since various organisms
constituting normal vaginal microflora have differing
susceptibilities to the detergent effect of the spermicides.
Spermicides may increase the risk of urogenital infection
through two mechanisms.[9] The first is direct toxicity for
lactobacilli. Lactobacilli in the vaginal vault are
hypothesized to perform a barrier function against
infection of the vaginal, perineal and urethral areas,
perhaps through production of hydrogen peroxide.
Nonoxynol is directly toxic to lactobacilli in concentrations
as dilute as 0.1%. By contrast, uropathogenic organisms
such as Proteus mirabilis, Staphylococcus, E. coli, and
Proteus mirabilis survive concentrations of nonoxynol as
high as 25%. Therefore, use of spermicides may indirectly
promote the growth of these organisms by acting against
lactobacilli. Candida albicans and other organisms that
cause vaginal fungal infection also survive high
concentrations of nonoxynol.[9] When used in conjunction
with a diaphragm, vaginal spermicides have been
implicated in asymptomatic bacteriuria, E. coli vaginal
colonization, and an increase of up to four times in the
risk of urinary tract infections.[9]
Allergic Reactions. Patients may also experience
contact dermatitis to spermicides.[9] In one case, a female
experienced a pruritic rash of unknown origin.[14] The rash
was thought to be coitally related since it only manifested
24 - 48 hours following coitus with her partner. As
physicians explored possible causes, they discovered
that the rash occurred in areas most often caressed by
her partner during sexual activity. The male applied
spermicidally lubricated condoms just prior to sex, and
did not wash residual spermicide from the hands.
Although the patient refused confirmatory testing, the
authors hypothesized the allergy was due to the
spermicide (texafor, not available in the U.S.) or a
perfuming agent.
Teratogenicity. A congressional hearing raised the issue
of possible teratogenicity and carcinogenicity of
spermicides.[15] Pending resolution of the question, the
FDA advised that it would examine the issue, but
eventually decided that sufficient evidence of
teratogenicity was lacking.
Duration of Activity
A major consideration for the female is the duration of
contraceptive activity of the various preparations. A relatively
recent agent is one of the few 24-hour nonprescription products
available. Known as Advantage 24, it remains on the vaginal
surface for a maximum of 72 hours, although the company only
labels it for a 24-hour duration.[13] Its long duration may increase
the riskof vaginal irritation. However, in research, the product was
better tolerated than a spermicidal suppository.
Current FDA Viewpoint Regarding Vaginal
Spermicides
In 1995, the FDA notified manufacturers that companies
marketing spermicides would be required to obtain approved
applications for all products since effectiveness would be
critically dependent on the final formulation.[15] Testing under
actual conditions of use would determine whether the
effectiveness of the products is unduly compromised when
genital secretions dilute them.
Teen Misconceptions
The pharmacist who counsels teen users of contraceptives must
be prepared to engage in frank discussion with a confused,
possibly embarrassed patient. In one case, a physician carrying
out a routine pelvic exam on a young patient noticed her vaginal
secretions were tinged an unnatural purple color. The teen had
used a grape jelly, thinking that what she heard about vaginal
contraceptive jelly was just that: jelly. The pharmacist is
obviously in an ideal clinical setting to teach teens about the
value of abstinence and provide instructions about confusing
products such as vaginal jellies, both before they are needed and
at the point of sale.
Spermicides and Protection Against
Sexually Transmitted Diseases:
General Precautions Regarding STDs
Vaginal contraceptives can never guarantee against contracting a
sexually transmitted disease (STD). The best defense against
this is abstinence prior to a mutually monogamous relationship in
which neither partner is infected with an STD or uses IV drugs.
However, many people fall short of this ideal.
Condoms are perhaps the next best method for STD prevention,
but women are not able to initiate condom use in many ethnic
groups due to cultural taboos, and condom rupture is a risk of
usage.[6,7] Therefore, it is prudent to examine vaginal
contraceptives in regard to their potential to prevent STDs.
Potential Spermicidal Activity Against STDs
Any discussion of the capabilities of a group of contraceptive
products must also take into consideration their ability to block
the transmission of STDs. The detergent action of spermicides is
thought to be virucidal through the same mechanisms by which
they destroy sperm, dissolving the lipid components of the viral
envelope.[4]
Nonoxynol-9 has been found experimentally to be virucidal in
vitro against herpes simplex virus type 2 and HIV type 1.[8] The
molecule acts against various other organisms responsible for
STDs, such as Treponema pallidum, Neisseria gonorrhoea,
Trichomonas vaginalis and Candida albicans.[4,9] However, the
use of a spermicide will not cure pre-existing infections from
these organisms. Further, as the majority of this work was
experimental, it is not known what activity the products actually
have in the genital tract. Thus, the FDA does not allow labeling
indicating activity against STDs. Despite this, one journal article
states, spermicides "have been widely recommended for the
prevention of HIV transmission..."[10] |
