SUCCESSFUL TREATMENT OF HYPOTHYROIDISM WITH RECTAL LEVOTHYROXINE

A CASE REPORT

Abstract

Introduction/BACKGROUND
Appropriate hormone replacement therapy is the
cornerstone of management and is typically in the form of
oral levothyroxine. The aim of this case report is to describe
an alternative route when the oral and parenteral routes are
not available.

CASE
Our patient was a 73-year-old male diagnosed with recurrent
transglottic squamous cell carcinoma (T2N0M0) and had
total laryngectomy, total thyroidectomy and bilateral neck
dissection done. Oral thyroxine replacement 100 mcg (1.3
mcg/kg/day) daily was started 3 days post operatively.
Patient’s post operative recovery was complicated with neck
wound breakdown with suspicion of pharyngo-cutaneous
fistula and was subsequently started on total parental
nutrition by day 12 post operation. Patient was referred
to endocrine team due to worsening hypothyroidism FT4
7.68 pmol/L (12.0-22.0) TSH 12.8 mIU/L (0.27-4.20). On
examination, patient was conscious, alert, GCS full, BP
127/75 mmHg, pulse rate 86 beats per minute, on vacuum
dressing over neck wound, reflexes normal, clinically
asymptomatic of hypothyroidism. Patient was converted to
per rectal administration of levothyroxine. Levothyroxine
tablet was crushed and mix with 10 mls of water and 20 mls
of lignocaine gel, pushed into rectum with nasogastric tube.
Patient was initially started on 2.6 mcg/kg/day per rectal
thyroxine and subsequently increased to 4 mcg/kg/day 5
days later due to the lack of adequate biochemical response.
Thyroid function normalized after 3 weeks of therapy, with
FT4 18.4 pmol/L (12.0-22.0) TSH 2.80 mIU/L (0.27-4.20).
Conclusion
In conclusion, per rectal administration of levothyroxine
can be a useful, safe, and effective alternative to oral
levothyroxine in conditions precluding oral administration.
We should advocate for increased availability of rectal
levothyroxine preparations worldwide.