Page 21 - Delaware Medical Journal - August, 2016

CASE REPORT
on hospital day three. Renal ultrasound on hospital day three showed no evidence of hydronephrosis or renal calculi.
DISCUSSION
There are multiple drugs that can cause intra-tubular crystal- induced obstruction, and lead to kidney injury. These drugs induce crystal formation directly because they are poorly soluble, or indirectly because their metabolites are poorly soluble. Drug induced crystalluria represents 1-2 percent of all renal calculi.1
FIGURE 2
Drugs commonly known to cause this kind of acute kidney injury include sulfonamide antibiotics, acyclovir, methotrexate, and protease inhibitors such as atazanavir and indinavir. Sulfonamides crystals may be amorphous (Figure 2), but the common morphologies include needle-shaped crystals and shocks of wheat (Figure 3). Both indinavir and acyclovir present as needles shaped crystals (Figures 4, 5). Other drugs such
as ethylene glycol and high dose vitamin C cause intratubular obstruction by causing calcium oxalate crystals (Figure 5).
Apart from the administration of these medications, there
FIGURE 4
C
Figure 2: Amorphous crystals of sulfonamides.
FIGURE 3
Figure 3: ‘Shocks of wheat’ (A) and needle-like (B) crystals of sulfonamides.
Figure 4: Indinavir crystals, rectangular plates of various sizes containing needle crystals (A) and a sheaf of densely packed needle crystals (B). Needle shaped crystals of Acyclovir (C).
Del Med J
| August 2016 | Vol. 88 | No. 8 245