HORMONAL THERAPY AND FAMILY PLANNING IN PORPHYRIA
INTRODUCTION
Female sex hormones,
based on oestrogen and gestagens (progesterone-like
agents), are commonly prescribed to women
under the following circumstances:
- For family planning (contraceptive) purposes
- For alleviation of symptoms of the menopause (change-of-life)
- For replacement of hormones following oophorectomy (removal
of the ovaries at the time of a hysterectomy).
These female sex
hormones may be dangerous in patients
with variegate porphyria (VP) or acute
intermittent porphyria (AIP). They should
never be prescribed or taken without careful
consideration as they may induce the acute
attack of porphyria.
SAFETY OF OESTROGENS AND GESTAGENS
Oestrogens and
gestagens are reported in most drug safety
lists to be unsafe in porphyria. There
is clear evidence that they have induced
the acute attack in some susceptible individuals
with very serious consequences. It is
our impression that the risk is greater
in patients with AIP than in those with
VP. This ties in with the observation
that patients with AIP are more likely
to have spontaneous exacerbations of their
porphyria during their menstrual cycle
and during pregnancy than are those with
VP. It is our impression that gestagens
may be more dangerous than the oestrogens.
That said, we are
aware of many patients with VP who have
taken such agents without ill effect.
It must be clearly understood however
that there is a risk associated with hormonal
therapy, and both patient and doctor must
understand this and exercise judgement
in deciding to proceed with it.
FAMILY PLANNING
Because of the
risks of hormonal contraception, the use
of non-pharmacological methods should
be considered in every woman with porphyria
requiring family planning. Therefore consideration
should be given to the use of the intrauterine
contraceptive device (IUCD), condoms,
the diaphragm, spermicidal jellies (which
are not significantly absorbed), and male
or female sterilisation. Hormonal contraception
may however be acceptable provided that
the precautions outlined below are observed.
HORMONAL REPLACEMENT FOR THE
MENOPAUSE
Hormonal therapy may be indicated for the
control of menopausal symptoms and also, long-term, for the prevention
of osteoporosis. These symptoms described for the menopause or "change-of-life".
They include hot flushes, palpitations and mood changes. (Note that
these symptoms are not due to the porphyria. Sometimes people with
porphyria wonder whether these symptoms are caused by the porphyria;
in fact they will be experienced by any woman undergoing the menopause
and have no direct bearing on porphyria.) Such symptoms can be disabling
and we are sympathetic to the use of hormonal therapy for their
control. Such therapy may be acceptable provided the precautions
outlined below are followed.
HORMONAL THERAPY FOLLOWING
OOPHORECTOMY
This is usually indicated because of severe
menopausal symptoms and the risk of premature osteoporosis in patients
who have had an oophorectomy. Hormonal replacement is often necessary
and one is therefore forced to try therapeutic replacement despite
the risks of inducing an acute attack. For this reason we would
urge gynaecologists to avoid performing oophorectomies at the time
of hysterectomy in patients with porphyria except where compelling
indications exist. This would obviate the need for compulsory early
replacement therapy with all its attendant risks.
PRECAUTIONS TO BE TAKEN WHEN
HORMONAL THERAPY IS PRESCRIBED
- Both doctor and patient must understand
that the the safety of this treatment
is not guaranteed.
- The patient must understand the need
to cease treatment and to report to
the doctor immediately should she experience
any abdominal pain.
- Do not use hormonal implants, or depot preparations such as
the two-monthly or three-monthly contraceptive injections. Once
administered these cannot be retrieved. Should the porphyria be
activated, withdrawal of the precipitating agent would be impossible.
- There is good evidence that gestagens
are more hazardous than oestrogens.
If possible use an oestrogen-only preparation.
Unfortunately, unopposed oestrogen use
may predispose to endometrial carcinoma.
This risk is removed where the patient
has had a hysterectomy; in other cases,
the hazards of unopposed oestrogen use
must be weighed against the additional
risk of a porphyric crisis which results
from a combined preparation.
- Low-dose preparations should be
used.
·Patients
with AIP must be regarded as being at
especially high risk, as must patients
with a history of acute attacks, particularly
where these have been associated with
the menstrual cycle.
WHAT TO DO IN THE EVENT OF
AN ADVERSE REACTION
The only adverse reaction to a hormonal preparation
which is due to the porphyria is an acute attack. The major symptoms
are abdominal pain, nausea, vomiting and red urine. Should this
arise, the patient should immediately stop treatment and report
to her doctor.
The doctor should:
- Test for an exacerbation of porphyria
by having a urine sample tested
for the presence of porphobilinogen
(read Acute
symptoms in porphyria).
- Advise the patient to desist from
further therapy until an acute attack
has been confidently excluded
- Arrange for the patient to receive
adequate treatment for the acute
attack, including access to haem
arginate, without delay (read
Management
of the acute attack).
HORMONAL THERAPY AND PORPHYRIA
CUTANEA TARDA
Since oestrogens
are implicated in the pathogenesis of
PCT, they should not be prescribed to
such patients until such time as the condition
has been fully treated and the patient
is in complete remission, after which
they may cautiously be restarted.
CONCLUSIONS
Although
female sex hormone therapy
may be possible in patients
with porphyria, it is at best
a risky undertaking and should
never be lightly undertaken.
Always try to make use of
other forms of intervention
where possible. If necessary,
have the patient retested,
both to confirm a diagnosis
and to assess the activity
of her porphyria before starting
therapy. Do not hesitate to
contact our centre for advice
when needed.
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